United States Court of Appeals
                         FOR THE EIGHTH CIRCUIT
                              _____________

                               No. 96-3221SI
                               _____________

Darryl Davis,                     *
                                  *
                Appellant,        *   Appeal from the United States
                                  *   District Court for the
     v.                           *   Southern District of Iowa.
                                  *
John Thalacker,                   *         [UNPUBLISHED]
                                  *
                Appellee.         *
                           _____________

                      Submitted:     April 18, 1997

                          Filed: May 6, 1997
                              _____________

Before RICHARD S. ARNOLD, Chief Judge, and FAGG and MURPHY, Circuit
     Judges.
                           _____________


PER CURIAM.


     Darryl Davis was charged in Iowa state court with driving
while intoxicated and driving with a suspended or revoked license.
According to the arresting officer, Davis was driving and traded
places   with   his   passenger,      Heather      Franzen,   as   the   officer
approached to stop Davis’s car.             Davis claimed Franzen was the
driver and subpoenaed her to testify as a material witness at his
trial.   Franzen had been charged with interference with official
acts for switching places with Davis, however, and with second-
degree burglary for unrelated acts.            Franzen’s prosecutor filed a
motion to quash Davis’s subpoena on the ground that Franzen would
assert her Fifth Amendment privilege against self-incrimination if
called to testify.     Following a hearing, the court sustained the
motion to quash.    The next day, a different prosecutor tried Davis,
who proceeded pro se with standby counsel, and a jury convicted
him.    A few days later, Franzen pleaded guilty to third-degree
theft, and the State dismissed the interference charge.


       Davis did not directly appeal his conviction, but later filed
a state postconviction action contending his right to compulsory
process   was   violated   when     the   trial   court   quashed   Franzen’s
subpoena.    The state postconviction court excused Davis’s failure
to file a direct appeal, finding Davis mistakenly believed he was
required to file appellate bonds, which he could not afford, and
Davis did not know about the plea bargain and its consummation.
The court did not find Franzen’s testimony would be favorable, but
concluded    it    would    be    “highly     relevant”     and   “especially
significant” because she was the only eyewitness besides the
arresting   officer.       The   court    concluded   the   “possibility   of
creating a conflict in [the] evidence . . . might create a
reasonable doubt for the jury.”           Holding the prosecutors’ failure
to inform Davis about Franzen’s pending plea agreement violated
Davis’s right to compulsory process, the court granted a new trial.
The Iowa Court of Appeals reversed, finding Davis had procedurally
defaulted his compulsory process claim by failing to appeal, and
the lower court’s reasons for excusing the failure were legally
insufficient.


       Davis then filed this federal habeas action renewing his
compulsory process claim.        The district court held Davis waived the
claim by failing to appeal in state court, and Davis failed to show
cause and prejudice to overcome the procedural default.                    The
district court saw no cause in Davis’s mistaken belief about the
bond requirement and the prosecutors’ failure to advise Davis of
Franzen’s plea negotiations.         The district also court concluded


                                      -2-
Davis had not shown prejudice because Davis did not show Franzen
would have testified favorably.      Davis appeals.


     Federal    courts   can   consider    the   merits   of   procedurally
defaulted claims if a petitioner shows cause for the default and
actual prejudice.    See Luton v. Grandison, 

, 628 (8th
Cir. 1994).     To establish cause, a petitioner must show some
objective factor external to the defense impeded the petitioner’s
efforts to comply with state procedural requirements.           See 

prejudice, a petitioner must show the alleged errors
worked to the petitioner’s actual and substantial disadvantage,
infecting the entire trial with constitutional error.            See 

Davis has shown cause, Davis loses because he has not
shown prejudice.    Davis has presented no evidence reflecting the
content of Franzen’s testimony.          Absent evidence that Franzen’s
testimony would have been favorable, Davis has not shown the
failure to compel Franzen’s testimony actually disadvantaged him
and infected his entire trial with error of a constitutional
magnitude.     The mere possibility that Franzen’s testimony might
create a conflict in the evidence is not enough to establish
prejudice for the purpose of federal habeas review.            See 

Franzen’s testimony would be favorable, Davis
cannot prevail on the merits of his claim anyway, whether he
characterizes it as a compulsory process claim or as a due process
claim.   See Pennsylvania v. Ritchie, 

, 56-57 (1987) (due
process right violated when government prevents criminal defendant
from discovering favorable evidence); United States v. Valenzuela-
Bernal, 

, 867 (1982) (right to compuslory process
violated only when criminal defendant makes plausible showing that
desired witness’s testimony would have been favorable to defense);


                                   -3-
United States v. Mejia-Uribe, 

, 399 (8th Cir.) (same),
cert. denied, 

(1996).


     Having considered and rejected all of Davis’s arguments, we
affirm the district court.


     A true copy.


          Attest:


               CLERK, U.S. COURT OF APPEALS, EIGHTH CIRCUIT.




                               -4-