A jury found Charles Smith guilty of manufacturing marijuana on his thirty-five acre farm in White Pine, Tennessee. The district court sentenced Smith to thirty-six months in prison followed by three years of supervised release, and ordered criminal forfeiture of three of the four tracts that, together, constitute Smith's farm. Both Smith and the government appeal, contesting the prosecution of this case under federal law, the validity of the search of Smith's farm, and the propriety of the district court's sentencing and forfeiture order. We affirm Smith's conviction and the forfeiture order, but we vacate Smith's sentence and remand the case for re-sentencing.

On August 28, 1989, the Tennessee Bureau of Investigation (TBI) obtained and executed a state search warrant to search Smith's residence, which is located on his farm. Although the TBI agents found no drugs in Smith's residence, a Tennessee Highway Patrol helicopter pilot who was simultaneously surveying Smith's farm reported to the agents that he had located a marijuana patch in Smith's cornfield. The agents then searched the entire farm and discovered fifty-two marijuana plants in the cornfield and seven plants in a seed bed beside a barn. The government later destroyed these plants before Smith had the opportunity to inspect or count them.

After Smith's arrest, the state referred this case to the federal government for prosecution under federal law. A federal grand jury indicted Smith on one count of intentionally manufacturing marijuana in violation of 21 U.S.C. § 841.1 The indictment also called for the forfeiture of Smith's farm pursuant to 21 U.S.C. § 853. Prior to trial, Smith filed a motion to suppress the government's evidence, arguing that TBI's search of his farm exceeded the scope of the state search warrant and thus violated Tennessee search and seizure law. Smith also filed a motion to dismiss the forfeiture action, arguing that, because the farm consisted of four separate tracts, the government could not seek forfeiture of the entire farm as a single unit. Instead, Smith argued, the court must treat each tract separately, and order forfeiture only of those tracts that the government proves that Smith actually used or intended to use to facilitate the manufacture of marijuana. Smith also argued that forfeiture of the farm would constitute cruel and unusual punishment in violation of the Eighth Amendment.

The federal magistrate who heard Smith's motions recommended that both be denied, and Smith appealed. The district court adopted the magistrate's recommendation to deny Smith's motion to suppress, holding that the federal "open fields" doctrine validated the search of the cornfield and the area around the barn. But the court deferred its decision on the forfeiture issues to allow the jury to decide first whether Smith used the farm, as a whole, to manufacture marijuana.

The government's key witness at trial was Smith's former co-worker, Cleveland Gardner. TBI agents discovered forty-eight marijuana plants on Gardner's property on August 18, 1989, ten days prior to their search of Smith's farm. Gardner testified that Smith grew the forty-eight plants in the seed bed near his barn and gave them to Gardner, who transplanted them to his own property.

At the close of the evidence, the court provided the jury with a verdict form that contained two questions: (1) whether Smith is guilty of unlawfully manufacturing marijuana, and (2) whether Smith used or intended to use his farm to commit or facilitate the commission of that offense. The court instructed the jury that the government must prove Smith's guilt beyond a reasonable doubt, but it need only prove Smith's use of the farm to commit the offense by a preponderance of the evidence. The jury answered both questions affirmatively.

At the sentencing hearing, the district court determined that Smith had manufactured over 100 marijuana plants, including those found in the cornfield (52), beside the barn (7), and on Gardner's property (48). The court overruled Smith's objection to the court's inclusion of the plants found at Gardner's residence. The court agreed with Smith, however, that it must consider each of the farm's four tracts separately for forfeiture purposes. The court then excluded Tract 3, on which Smith's residence is located, from the forfeiture order. Finally, the court imposed a thirty-six month prison sentence, followed by three years of supervised release.

Smith attacks his conviction by raising two arguments that we need not discuss in depth in light of this court's recent decision in United States v. Allen, 954 F.2d 1160 (6th Cir.1992).2

First, Smith argues that the state's referral of this case for federal prosecution violated his rights to due process and equal protection because there are no guidelines to regulate such referrals. But as this court held in Allen, "due process does not mandate that referrals be controlled through policy as long as prosecutors are not acting as rubber stamps and exert their own discretion as to whether or not to prosecute." Id. at 1166. Smith, like the defendant in Allen, offers no evidence of "rubber-stamping" in this case, and thus he "has failed to demonstrate that his due process or equal protection rights have been violated." Id.

Second, Smith argues that the district court erred in denying his motion to suppress because TBI's search of Smith's property violated Tennessee search and seizure law, which Smith argues does not recognize the federal "open fields" doctrine. But as the Allen court explained when it rejected this argument, "[t]he state may reserve certain rights including a stricter standard of search and seizure law; however, such a standard does not have to be applied in federal court." Id. at 1168 (citing United States v. Loggins, 777 F.2d 336, 338 (6th Cir.1985)). Federal search and seizure law applies in this federal prosecution, and Smith does not allege that TBI's search was illegal under federal law.

We affirm Smith's conviction.

Smith attacks his prison sentence with two arguments that this court addressed in Allen. First, Smith argues that the government's destruction of the marijuana plants before Smith had the opportunity to count them resulted in a violation of his due process rights. In the absence of bad faith, however, the government's destruction of the plants does not constitute a violation of due process. Allen, 954 F.2d at 1168-69. Because Smith neither alleges nor offers evidence of bad faith on the government's part, we find no due process violation in this case.3

Second, Smith contends that 21 U.S.C. § 841(b)(1)(B) and U.S.S.G. § 2D1.1(c) (Drug Quantity Table), which provide a minimum five-year sentence for the manufacture of 100 or more marijuana plants regardless of their weight, violate due process and equal protection rights. Like Allen, Smith first raised this argument in a motion for correction of sentence pursuant to Federal Rule of Criminal Procedure 35, and the district court denied the motion because Smith had already filed an appeal from the court's judgment. We agree with the government that Smith's case, like Allen's, is not an "exceptional case" that justifies our consideration of this issue that the district court did not consider. Allen, 954 F.2d at 1168.

The government also attacks Smith's prison sentence, arguing that the district court erred in imposing a sentence less than the statutory minimum of five years. We agree. Congress requires that, in the case of a violation involving 100 or more marijuana plants, the defendant "shall be sentenced to a term of imprisonment which may not be less than 5 years." 21 U.S.C.A. § 841(b)(1)(B) (West Supp.1992). After receiving evidence that Smith has a heart condition that leaves him with a fifty percent chance of surviving for two years, the district court imposed a sentence of only thirty-six months. The Sentencing Guidelines provide that where, as here, "the statutorily required minimum sentence is greater than the maximum of the applicable guideline range, the statutorily required minimum sentence shall be the guideline sentence." U.S.S.G. § 5G1.1(b) (Nov.1991). Despite Smith's compelling circumstances, the district court had no discretion to impose a sentence below the statutory minimum. United States v. Hodges, 935 F.2d 766, 772 (6th Cir.), cert. denied, --- U.S. ----, 112 S. Ct. 251, 116 L. Ed. 2d 206 (1991). Because the court imposed a sentence less than the statutorily required minimum, we vacate the court's sentence.4

Both parties appeal from the district court's order requiring criminal forfeiture of three of the four tracts that constitute Smith's farm. Smith contends that the district court erred by holding that the government need only prove its forfeiture case by a preponderance of the evidence. The government argues that the court erred by holding that each of the four tracts that constitute the farm must be treated as separate units of "property" for forfeiture purposes. Both parties contest the court's determinations as to which of the four tracts are forfeitable.

1. The Standard of Proof under 21 U.S.C. § 853

To obtain criminal forfeiture under section 853, the government must show that the property in question fits one of the three categories of property described in section 853(a).5 Subsection (a) does not specify the standard of proof under which the government must make this showing. Subsection (d), however, creates a rebuttable presumption that the convicted person's property "is subject to forfeiture under this section if the United States establishes by a preponderance of the evidence that" the person acquired the property during, or within a reasonable time after, the period of the violation, and that the violation was the only likely source for the property. 21 U.S.C.A. § 853(d) (West Supp.1992) (emphasis added). The statute does not clarify whether Congress intended to apply the preponderance standard to the government's overall burden of proving which property defendants must forfeit under subsection (a). We recognize three plausible interpretations of what Congress intended when it drafted section 853.

First, Congress may have intended that the government be able to create the presumption under subsection (d) using the preponderance standard, but that the government must ultimately prove that the property is subject to forfeiture under subsection (a) beyond a reasonable doubt. The Third Circuit rejected this construction "as inconsistent with Congressional intent" in United States v. Sandini, 816 F.2d 869, 875 (3rd Cir.1987). The Seventh and Ninth Circuits follow Sandini. See United States v. Hernandez-Escarsega, 886 F.2d 1560, 1577 (9th Cir.1989) ("It would make little sense ... to provide for a rebuttable presumption that certain property is subject to forfeiture if facts relative to that property are established by a preponderance of the evidence, then move to a beyond-the-reasonable-doubt standard before the property could be forfeited."), cert. denied, --- U.S. ----, 110 S. Ct. 3237, 111 L. Ed. 2d 748 (1990); United States v. Herrero, 893 F.2d 1512, 1541-42 (7th Cir.) (stating approval of Sandini ), cert. denied, 496 U.S. 927, 110 S. Ct. 2623, 110 L. Ed. 2d 644 (1990); United States v. Simone, 931 F.2d 1186, 1197-99 (7th Cir.) (district court erred by instructing jury that government can create a rebuttable presumption with a preponderance of the evidence but must ultimately prove the property to be forfeitable beyond a reasonable doubt), cert. denied, --- U.S. ----, 112 S. Ct. 584, 116 L. Ed. 2d 609 (1991). A panel of the Eleventh Circuit rejected the Sandini view in United States v. Elgersma, 929 F.2d 1538, 1548 (11th Cir.1991),6 but that circuit has since vacated the panel opinion and granted rehearing en banc. United States v. Elgersma, 938 F.2d 179, 180 (11th Cir.1991).

A second interpretation of section 853 is that, although the government must prove that the property is subject to forfeiture under subsection (a) beyond a reasonable doubt, subsection (d) provides an exception to this higher standard and allows the government to prove that the property constitutes "proceeds" of the offense by creating the presumption with a preponderance of the evidence. Property subject to forfeiture under subsection (a) includes proceeds from the offense (section 853(a)(1)), property used to commit or facilitate the commission of the offense (section 853(a)(2)), and property that gives the person a source of control over a continuing criminal enterprise (section 853(a)(3)). The presumption that subsection (d) provides, however, applies only to proceeds of the offense. Language in section 853's legislative history reveals that Congress intended to ease the burden on the government's attempt to prove that property constitutes proceeds of the offense. See S.Rep. No. 225, 98th Cong., 2d Sess. 212 (1984), reprinted in 1984 U.S.C.C.A.N. 3182, 3395 (subsection (d) establishes a permissive inference under "certain circumstances which are indicative of the fact that particular property" represents proceeds of drug transactions because "it is often difficult to produce direct evidence that particular property of a defendant constitutes, or was purchased with, such proceeds"). No federal court of appeals, however, has construed section 853 to differentiate between proceeds of the offense and other property on the burden of proof necessary for forfeiture.

The third possible interpretation of section 853 infers from Congress' reference to the preponderance standard in subsection (d) that Congress intended that standard to apply under subsection (a) as well. The Third, Seventh, and Ninth Circuits concluded that this interpretation best represents Congress' intent. Sandini, 816 F.2d at 876; Simone, 931 F.2d at 1199; Hernandez-Escarsega, 886 F.2d at 1577.

Like the statutory language itself, courts have interpreted the legislative history of section 853 differently on this point. Some language in the Senate report implies that Congress intended the beyond-a-reasonable-doubt standard to apply under subsection (a). See S.Rep. No. 225 at 196 & 210, reprinted in 1984 U.S.C.C.A.N. at 3379 & 3393 (one advantage of civil forfeiture under 21 U.S.C. § 881 over criminal forfeiture under section 853 is that "the government's burden of proof is lower" in civil cases). The Third Circuit, however, concluded that other language in the Senate report implies that Congress intended that the lower burden apply. See Sandini, 816 F.2d at 876 (concluding from the report's discussion of subsection (d) that "[t]he legislative history makes clear that Congress sought to make the government's burden of proof in criminal forfeitures the same as that in the civil realm"). The Elgersma panel, which found that the higher burden applies, concluded that "the legislative history itself is inconclusive." 929 F.2d at 1546.

Finding no clear guidance from Congress, the federal circuits that have considered this issue have focused on the nature of a criminal forfeiture proceeding. The Third Circuit in Sandini relied on the mandate of subsection (a) that the court order forfeiture "in addition to any other sentence," and concluded that "[f]orfeiture is not an element of the ... offense, but simply an additional penalty for that proscribed conduct." 816 F.2d at 875. The court reasoned that, because the elements of a criminal offense must be proved beyond a reasonable doubt, while the preponderance standard applies to statutorily enhanced punishments, Congress intended that the lower standard apply to the punishment of criminal forfeiture. The Elgersma panel, however, concluded that "beyond a reasonable doubt is the proper standard [because] criminal forfeiture is not punishment, but a criminal charge to be proved like any other." 929 F.2d at 1548. Those judges determined that criminal forfeiture is a "substantive criminal charge" because some criminal procedures apply to criminal forfeiture proceedings. Id.7

We decide to follow existing federal circuit precedent on this close issue, and hold that the government must prove that property is subject to criminal forfeiture under section 853(a) by a preponderance of the evidence. We agree with Sandini that this holding best represents the nature of a criminal forfeiture proceeding as Congress intended it. However ambiguous section 853 may be, it expressly provides that a court shall order criminal forfeiture "in addition to any other sentence" at the time that it imposes the sentence. Although a criminal forfeiture proceeding bears some characteristics of a criminal matter, its purpose is to determine the proper punishment for the charged offense once the defendant's guilt on that charge has been proved beyond a reasonable doubt. By requiring proof by a preponderance of the evidence, we acknowledge the purpose of criminal forfeiture and ensure that it serves as the efficient alternative to civil forfeiture that Congress intended it to be. See S.Rep. No. 225 at 196-97, reprinted in 1984 U.S.C.C.A.N. at 3379-80. We thus find no error in the district court's instruction on the government's standard of proof.

2. Should the farm be treated as four separate units?

Section 853(a)(2) requires forfeiture of all of the "property" that a defendant uses or intends to use to commit or facilitate the commission of an offense, even if the defendant uses only part of that "property" for that purpose. See United States v. Littlefield, 821 F.2d 1365, 1367 (9th Cir.1987) (because section 853(a)(2) requires forfeiture of property used "in any manner or part," all is subject to forfeiture even when only part is used); United States v. Harris, 903 F.2d 770, 777 (10th Cir.1990) (following Littlefield ).8

We must then determine what constitutes Smith's "property" under section 853. The government contends that Smith's farm is his "property" and thus, if Smith used any of it to facilitate the offense, he must forfeit all of it. Smith argues that we must treat each of the four tracts that constitute the farm as a separate piece of "property" under section 853. Neither party cites, nor have we found, an opinion of any federal circuit that addresses this particular question of the identification of tracts of real property subject to forfeiture under section 853. The Fourth Circuit, however, has addressed this issue in the context of civil forfeiture under section 881, and concluded that the property must be defined by the recorded instruments and documents that created the defendant's interest in the property. See United States v. Santoro, 866 F.2d 1538, 1543 (4th Cir.1989); United States v. Reynolds, 856 F.2d 675, 677 (4th Cir.1988).

In Reynolds, the appellant contested the district court's order that required her to forfeit a thirty acre parcel that she possessed under a lease with an option to purchase, arguing that she had used only a small portion of the parcel to commit drug offenses. The Fourth Circuit noted that section 881 requires forfeiture of "the whole of any lot or tract of land ... which is used ... in any manner or part," and held that such a "tract" must be defined by "the natural source for its definition: the instrument creating an interest in the property." Id. at 676-77. Because the lease defined the thirty acre parcel as a single tract, the court affirmed forfeiture of the entire parcel. Id. Santoro involved the forfeiture of a twenty-six acre tract of land that was bisected by a road. The defendant-landowner treated the portions on each side of the road as two separate tracts, and the property had even been taxed as two separate parcels. 866 F.2d at 1540. But the deed by which the owner obtained her interest in the property described it as a single, undivided tract. Id. Relying on Reynolds, the Fourth Circuit rejected the owner's argument that the tract constituted two separate pieces of "property" for forfeiture purposes and held that the forfeited property "must be determined from the duly recorded instruments and documents filed in the county offices where the defendant property is located." Id. at 1543. "The [owner's] subjective characterization of the property as two tracts," the court held, "cannot serve as the legal basis" for determining "property" under section 881. Id.

Because of the similarities in the language and purpose of the two statutes on this point, we believe that the Fourth Circuit's property-identification rule is correct for criminal forfeiture under section 853 as well as civil forfeiture under section 881. See Littlefield, 821 F.2d at 1367-68 (the government can "accomplish in a criminal forfeiture proceeding under section 853 precisely what it could do through a separate civil forfeiture proceeding under section 881"). Thus, we hold that tracts of real property subject to forfeiture under section 853 are defined by the instruments and documents that created the defendant's interest in the property.9

Our application of this rule to the present facts, however, is complicated. Smith initially obtained his interest in the farm by virtue of four separate conveyances of four separate tracts to Smith and his former wife, Linda, on four separate dates between 1978 and 1984. The four tracts are taxed separately and have been the subject of separate deeds of trust. Smith and Linda divorced in 1985, at which time Linda conveyed all of her interest in all four tracts to Smith by a single quitclaim deed, which Smith recorded. The government contends that, because the quitclaim deed conveyed all four tracts as one single unit, the entire farm constitutes the "property" that is subject to forfeiture. The government finds support for this result in the fact that Smith treated the farm as one single unit, and in the forfeiture statute's instruction that its provisions "shall be liberally construed to effectuate its remedial purposes." 21 U.S.C.A. § 853(o) (West Supp.1992). Smith counters that we should treat each of the four tracts separately because the quitclaim deed did not actually create his interest in the farm. Smith reasons that he and Linda, who were married when they obtained their interest in the four tracts, held the tracts as tenants by the entirety, and thus they owned the tracts as if they were one person, each of them taking the whole. Thus, Smith argues, Linda did not actually convey any interest to him under the quitclaim deed, but instead simply forfeited her own interest to allow Smith to hold the tracts in fee simple alone.

We resolve this issue by applying Tennessee's law governing tenancies by the entirety.10 Under that law, a deed that creates a tenancy by the entirety gives each spouse an interest in the whole indivisible estate. Thus, the husband and wife each become "the owner of the whole from the moment of the conveyance to them." Robinson v. Trousdale County, 516 S.W.2d 626, 628 (Tenn.1974) (quoting Cole Mfg. Co. v. Collier, 95 Tenn. 115, 31 S.W. 1000, 1001 (1895)) (emphasis added). Together, "[t]hey take but one estate, as a corporation would take, being by the common law deemed but one person, and, if one die, the estate continues in the survivor, the same as if a corporator were to die." Beddingfield v. Estill & Newman, 118 Tenn. 39, 100 S.W. 108, 110 (Tenn.1907). When one spouse dies, "the survivor ... takes and becomes vested of the entire estate--a fee simple estate--by virtue of the grant or deed conveying the property to them." Id. (emphasis added). "On the death of husband or wife, the survivor take no new estate or interest--nothing that was not in him or her before. It is a mere change in the properties of the legal person holding--not of the legal estate holden." Id. We thus conclude that Smith initially obtained his interest in the whole of each of the four tracts by virtue of the four separate deeds.

Because the government relies on the quitclaim deed that Linda delivered to Smith, we must determine the effect that deed had on Smith's interest in the property. Tennessee's Supreme Court addressed this question in another context and concluded that, "when [one spouse] transferred his interest [in a tenancy by the entirety] to his wife ..., she became the owner in fee simple absolute, just as she would have done had he predeceased her." Barry v. Woods, 594 S.W.2d 687, 689 (Tenn.1980) (emphasis added). Linda's transfer of her interest in the four tracts, therefore, did not actually create Smith's interest in the land any more than Linda's death would have. Smith obtained his interest in the farm by the four separate deeds that created four separate tenancies by the entirety.11 Because the four separate deeds actually created Smith's interest in the land that now constitutes his farm, we find no error in the district court's decision to treat each tract separately for forfeiture purposes.

3. Which tracts should be forfeited?

Smith does not contest the forfeiture of Tract 1, on which the officers discovered the marijuana patch in the cornfield. But Smith argues that the evidence is insufficient to support the finding that he used Tracts 2 or 4 to commit or facilitate commission of the offense. The government contends that the court erred in exempting Tract 3 from the forfeiture order.

The district court ordered forfeiture of Tract 2 because it found that the seed bed was located on that tract, and Smith contends that there is insufficient evidence to support this finding. We disagree. Gardner testified that, "[i]f you are standing looking straight at the barn, [the seed bed] was right on the left of it near the edge of the woods." The government's exhibits show that the barn, which is located on Tract 2, borders and faces Tract 1. As one looks "straight at the barn," the area to the left which Gardner designated as the area containing the seed bed is located on Tract 2. The evidence thus supports the district court's finding that Smith used Tract 2 to manufacture marijuana.

Smith contends that the forfeiture of Tract 4 was in error because he grew no marijuana on that tract. The government argues that, because the cornfield in which the officers located the large marijuana patch extended across Tract 1 and Tract 4, Tract 4 "facilitated" the commission of the offense by concealing the patch on Tract 1. To "facilitate" the commission of the offense under section 853, the property in question must bear a "sufficient nexus" or "substantial connection" to the underlying criminal activity. See United States v. $22,287, United States Currency, 709 F.2d 442, 447 (6th Cir.1983) (requiring "nexus" under section 881); Harris, 903 F.2d at 777-78 (requiring "nexus" under section 853); United States v. Parcel of Land & Residence at 28 Emery St., 914 F.2d 1, 3-4 (1st Cir.1990) (requiring "substantial connection" under section 881). We hold that, when the defendant uses real property to actually physically conceal the commission of the offense on adjacent property, the nexus is sufficient to support a finding that the property "facilitated" commission of the offense under section 853(a)(2). The district court found that Tract 4 helped to actually physically conceal the marijuana patch on Tract 1, and the evidence supports this finding. We thus find no error in the district court's determination that Tract 4 facilitated commission of the offense.

Finally, the government contends that the district court erred in finding that Smith did not use Tract 3, on which his residence was located, to facilitate commission of the offense. Although the agents found no marijuana in the residence or on Tract 3, the government argues that Smith used the residence to guard the marijuana and to conceal the entire operation by making the farm appear to be a legitimate use of the land. The record contains no evidence that Smith used the house to "guard" the marijuana, so we need not decide whether this use would create a sufficient nexus to warrant forfeiture. And we find no error in the district court's conclusion that the mere presence of the residence on Tract 3 did not provide the type of concealment sufficient to "facilitate" the offense. We do not hold that an offense can never be facilitated by a defendant's use of property in a manner that creates the appearance that adjacent property is used for legitimate purposes, but neither will we require this result as a matter of law.

4. Cruel and Unusual Punishment?

Smith contends that the forfeiture of Tracts 1, 2, and 4, combined with his prison sentence, constitute cruel and unusual punishment because the value of the land, which the evidence suggests may be near $1,000,000, is disproportionate to the relatively small number of marijuana plants involved. Even if we assume, however, that a forfeiture order under section 853 is subject to the Eighth Amendment's prohibition, this order is neither "cruel and unusual" nor grossly disproportionate to the crime. See Harmelin v. Michigan, --- U.S. ----, 111 S. Ct. 2680, 115 L. Ed. 2d 836 (1991); Solem v. Helm, 463 U.S. 277, 103 S. Ct. 3001, 77 L. Ed. 2d 637 (1983). Congress, in fact, has provided for a fine of up to $2,000,000, in addition to a forty-year prison sentence, for the manufacture of 100 or more marijuana plants. See 21 U.S.C.A. § 841(b)(1)(B) (West Supp.1992). We thus reject Smith's Eighth Amendment argument.

We AFFIRM Smith's conviction and the forfeiture order, VACATE his sentence, and REMAND the case for re-sentencing in accordance with this opinion.

RALPH B. GUY, Jr., Circuit Judge, concurring in part and dissenting in part.

I concur in all of Judge Reavley's well-reasoned opinion, except that portion dealing with the forfeiture of the farmhouse. Forfeiture is intended to be a harsh sanction. It is intended not only to take the profit out of drug dealing but also to make persons give serious consideration prospectively as to whether the potential gain is worth the downside risk. I would not try to formulate any type of per se rule relative to forfeitures, but simply analyze each situation on a case-by-case basis. Here, the defendant had a relatively small farm, with a farmhouse located on the property. I would treat the property as one entity, notwithstanding how it was acquired historically, and declare it all forfeitable. For all practical purposes, the property was treated as a unit, and the house certainly was the "command post" for whatever was occurring on the property, be it growing marijuana or legitimate activities. There well may be a point at which a defendant's constitutional rights will mandate that the proportionality of the forfeiture to the offense be considered. This case is far short of such a point, however.