In the

    United States Court of Appeals
                 For the Seventh Circuit
                     ____________________
No. 19-1085
OSAMA TAHA,
                                                  Plaintiff-Appellant,
                                 v.

INTERNATIONAL
BROTHERHOOD OF
TEAMSTERS, Local 781,
                                                 Defendant-Appellee.
                     ____________________

         Appeal from the United States District Court for the
           Northern District of Illinois, Eastern Division.
           No. 18-cv-01201 — Charles P. Kocoras, Judge.
                     ____________________

  ARGUED SEPTEMBER 19, 2019 — DECIDED JANUARY 13, 2020
                ____________________

   Before SYKES, HAMILTON, and BRENNAN, Circuit Judges.
    BRENNAN, Circuit Judge. Federal law imposes a duty on un-
ions to fairly represent all employees in their bargaining units.
Osama Taha sued his union, arguing it breached that duty af-
ter his employer fired him for abandoning his job. Although
the union grieved Taha’s firing, he alleges it did so unfairly.
He also contends the union wrongfully shut down his
2                                                  No. 19-1085

grievance process. The district court dismissed Taha’s second
amended complaint for failure to state a claim, finding it gave
no details to support any allegation of unlawful union con-
duct. Our review compels the same conclusion. Because
Taha’s complaint fails to state a plausible claim for relief, we
affirm.
                               I
    United Airlines hired Taha in 1988 and laid him off in
2003. He retained recall rights to his position under a collec-
tive bargaining agreement (“CBA”) between the airline and
his union, the International Brotherhood of Teamsters, Local
781. After a twelve-year furlough, United offered Taha an op-
portunity to return to work at O’Hare Airport in Chicago,
which he accepted.
    About three weeks into this new job, Taha learned his
mother had suffered a heart attack. Because she lived in Saudi
Arabia, Taha asked for time off to travel and care for her. Taha
wanted six months; United gave him 30 days. He sought to
extend his leave by reaching out to several people for help,
among them Carla Starck, a human resources representative
with United. Starck told Taha that United’s operations man-
agement department had the final say on an extension. Taha
also spoke with the union’s president, Paul Stripling, who
told him to trust in the union’s process.
   United denied Taha’s extended-leave request in a letter
sent to his home in Indiana. But Taha never saw it, as he re-
mained in Saudi Arabia throughout his leave. Nor did he re-
turn to work, which the airline construed as job
abandonment. Three months after United expected Taha back
on the job, he was fired.
No. 19-1085                                                             3

   Taha grieved his firing through the union. The CBA re-
quired Taha, with the union’s help, to first attempt to resolve
the dispute through a series of informal exchanges with
United. Those exchanges included supervisor discussions as
well as a written complaint and answer process. After that, if
the dispute remained unsettled, the CBA required Taha and
United to take the grievance before a body known as the Joint
Board of Adjustment (“JBA”). Taha’s grievance culminated in
a JBA hearing, and Stripling represented Taha in that pro-
ceeding.
    The JBA unanimously denied Taha’s grievance. Stripling
notified Taha about the JBA’s decision in a letter saying: “The
board has denied your grievance. Good luck in your future
endeavors.” In response, Taha asked the union to demand ar-
bitration from United. But the union showed no urgency in
answering him, waiting over six months to reply. When the
union finally responded, it explained that the CBA barred fur-
ther pursuit of his grievance.
    Taha then sued the union, alleging it breached its duty to
fairly represent him under the Railway Labor Act, 45 U.S.C.
§§ 151–188.1 His pleadings proceed in pairs. He filed two
amended complaints, with the second alleging two separate
incidents: the union’s handling of his JBA hearing, and its
post-hearing refusal to arbitrate. He also pleaded only two
facts to support his breach claims: (1) before the JBA hearing
began, Taha overheard Stripling and Starck “chatt[ing] gen-
ially” about Starck acquiring airline tickets for some of Strip-
ling’s friends; and (2) during the hearing, Stripling “told Taha


    1 The Railway Labor Act governs unions in the air transportation busi-

ness. See 45 U.S.C. § 181.
4                                                     No. 19-1085

to remain silent” and “prevented Taha from presenting sev-
eral strong and important exhibits.”
     The union moved to dismiss Taha’s second amended com-
plaint under Federal Rule of Civil Procedure 12(b)(6), arguing
it failed to allege enough facts to support an unfair represen-
tation claim. It also argued Taha’s complaint was time-barred.
The district court agreed with the union and dismissed Taha’s
complaint for both reasons. This appeal followed.
                                II
   We begin our analysis with the Rule 12(b)(6) dismissal be-
fore turning to the timeliness of Taha’s complaint.
    The dismissal of a complaint under Rule 12(b)(6) warrants
de novo review. Spiegel v. McClintic, 

, 616 (7th Cir.
2019). We construe the complaint in the light most favorable
to plaintiff, accept all well-pleaded facts as true, and draw rea-
sonable inferences in plaintiff’s favor. Yeftich v. Navistar, Inc.,

, 915 (7th Cir. 2013) (affirming Rule 12(b)(6) dis-
missal of unfair representation claim).
    Federal Rules of Civil Procedure 8 and 12 set the condi-
tions for a sufficient pleading. Rule 8(a)(2) says a complaint
“must contain … a short and plain statement of the claim
showing that the pleader is entitled to relief.” If a complaint
falls short of this requirement, it risks dismissal under Rule
12(b)(6) for “failure to state a claim upon which relief can be
granted.” A claim satisfies Rule 8(a)(2)—and avoids dismissal
under Rule 12(b)(6)—if the complaint alleges facts that show
the claim is “plausible on its face.” Bell Atl. Corp v. Twombly,

, 570 (2007). “A claim has facial plausibility when
the plaintiff pleads factual content that allows the court to
No. 19-1085                                                       5

draw the reasonable inference that the defendant is liable for
the misconduct alleged.” Ashcroft v. Iqbal, 

, 678
(2009).
    Rule 8(a)(2) prescribes what a pleading must show;
Twombly and Iqbal clarify that rule’s demands. In the wake of
those cases, a complaint must include facts showing a plausi-
ble—not merely “conceivable”—entitlement to relief. 

. When a complaint’s facts “do not permit the
court to infer more than the mere possibility of misconduct,
the complaint has alleged—but it has not ‘shown’—’that the
pleader is entitled to relief.’” 

(quoting FED. R. CIV. P.
8(a)(2)). That means a complaint must plead “more than an
unadorned, the-defendant-unlawfully-harmed-me accusa-
tion.” 

“Nor does a complaint suffice if it tenders
‘naked assertions’ devoid of ‘further factual enhancement.’”

550 U.S. at 557) (internal brackets omit-
ted). In keeping with these principles, when considering the
viability of a claim in the face of a Rule 12(b)(6) challenge, we
may reject sheer speculation, bald assertions, and unsup-
ported conclusory statements. See 

;

, 681; 

.
                                 A
    Taha argues the second amended complaint states a plau-
sible unfair representation claim. To make that assessment,
we must first say a few words about the source of the union’s
duty and the ways Taha alleges it was breached.
    The duty of fair representation arises out of a union’s role
as the exclusive representative of all employees in a collective
bargaining unit. See Vaca v. Sipes, 

, 177 (1967); see
also Bishop v. Air Line Pilots Ass’n, Int’l, 

, 397 (7th
6                                                               No. 19-1085

Cir. 2018) (describing the duty as judicially implied under the
Railway Labor Act). Because a union serves as the exclusive
bargaining agent for those employees, it has a corresponding
legal obligation “to serve the interests of all members without
hostility or discrimination toward any, to exercise its discre-
tion with complete good faith and honesty, and to avoid arbi-
trary conduct.” Id.2 That obligation applies equally to all
aspects of representational activity. 

.
    Bringing those elements together, the duty of fair repre-
sentation covers all union activity and a breach occurs “only
when a union’s conduct toward a member of the collective
bargaining unit is arbitrary, discriminatory, or in bad faith.”

(extending duty to grievances and arbi-
tration). Taha asserts arbitrary conduct and bad faith claims.
On appeal, as in the district court, he argues each claim
emerges out of the union’s representation at the JBA hearing
and its refusal to pursue arbitration against United. We must
decide whether those claims meet the requirements imposed
by Rule 8(a)(2). We begin with Taha’s claim of arbitrary con-
duct.
                                       1
   A “union’s actions are arbitrary only if, in light of the fac-
tual and legal landscape at the time of the union’s actions, the
union’s behavior is so far outside a wide range of reasonable-
ness, as to be irrational.” Air Line Pilots Ass’n, Int’l v. O’Neill,


    2 Vaca v. Sipes, 

(1967), involves a National Labor Relations

Act violation, while Taha asserts a violation of the Railway Labor Act. The
duty of fair representation as articulated in Vaca applies interchangeably
to claims under either statutory scheme. Bishop v. Air Line Pilots Ass’n, Int’l,

, 397 n.22 (7th Cir. 2018).
No. 19-1085                                                              7

, 67 (1991). A charge of arbitrary union conduct re-
quires “an objective inquiry,” 

(citation
omitted), and we apply an “extremely deferential standard”
to the union’s strategic choices, McKelvin v. E.J. Brach Corp.,

, 867 (7th Cir. 1997). See Garcia v. Zenith Elecs.
Corp., 

, 1177 (7th Cir. 1995) (“We must defer to the
[u]nion’s strategic choices unless they are irrational.”). At the
pleading stage, Taha need not prove that the union acted ir-
rationally; that said, he “must include enough details about
the subject-matter of the case to present a story that holds to-
gether.” Runnion ex rel. Runnion v. Girl Scouts of Greater Chi. &
Nw. Ind., 

, 526 (7th Cir. 2015) (citation and internal
quotation marks omitted).
    We start with whether Taha’s second amended complaint
showed an irrational refusal to arbitrate. Taha’s second
amended complaint says arbitration is “the next step” in his
grievance process. That is incorrect. Article 19 of the CBA al-
lows the union to arbitrate grievances only if the JBA dead-
locks.3 In Taha’s case, the JBA’s decision was unanimous,
which means he reached the end of the line for his grievance
options. See 

(holding no employee has
“an absolute right to have his grievance taken to arbitration
regardless of the provisions of the applicable collective bar-
gaining agreement”). Far from irrational, the union adhered
to the CBA’s terms when it declined Taha’s arbitration de-
mands, so we see no basis for reversal on that point.



    3 Although not attached to the complaint, the district court considered

the CBA because it was referred to in the second amended complaint, un-
disputed, and central to Taha’s claims. See Williamson v. Curran, 

, 436 (7th Cir. 2013).
8                                                   No. 19-1085

    Taha’s claim of irrational representation at the JBA hear-
ing fares no better. On appeal, he contends the union “com-
promised” his JBA hearing when it told him not to testify and
ignored “several strong and important exhibits.” The allega-
tion that the union compromised his JBA hearing is missing
from Taha’s second amended complaint. Yet “[a] party ap-
pealing a Rule 12(b)(6) dismissal may elaborate on his factual
allegations so long as the new elaborations are consistent with
the pleadings.” Geinosky v. City of Chicago, 

, 745-46
n.1 (7th Cir. 2012) (citations omitted). So we consider Taha’s
elaboration.
    Three problems arise with Taha’s claim. First, a predicate
to a compromised JBA hearing is that the grievance was not a
flop regardless of the union’s role. To draw the reasonable in-
ference of a compromised hearing, Taha must allege facts
“plausibly suggesting (not merely consistent with)” a valid
grievance. 

; see also 

. Taha need not prove at the pleading stage that United
wrongly fired him. But he must “present a story that holds
together,” Runnion ex rel. 

, and his
“[f]actual allegations must be enough to raise a right to relief
above the speculative level.” 

. Taha
pleaded no basis, let alone a plausible basis, to challenge his
firing. Nor does Taha explain in his complaint or on appeal
why he believed he could remain on leave three months
longer than United allowed. And he does not point to facts
suggesting United improperly fired him or treated him differ-
ently than any other employee who refused to return to work.
So we cannot plausibly infer that Taha encountered a compro-
mised JBA hearing.
No. 19-1085                                                     9

    Second, in unfair representation claims, a “[f]ailure to pre-
sent favorable evidence during the grievance process” consti-
tutes a breach of duty “only if that evidence probably would
have brought about a different decision.” 

(citation and internal quotation marks omitted). What
evidence did the union adversely exclude here? Taha had
chances to explain in two amended complaints, during the
motion to dismiss proceedings, in two briefs on appeal, and
even at oral argument. At each opportunity, he offered no ex-
planation. Nor did Taha cite instances at his JBA hearing
when this unidentified evidence might have been helpful. The
complaint is silent on these critical details, and Taha offers no
elaboration about them on appeal. Without any description of
the excluded evidence, we cannot plausibly infer that such ev-
idence might have swayed the JBA to reach a different deci-
sion.
    Third, a “union is accorded considerable discretion in
dealing with grievance matters.” 

(deferring to un-
ion’s decision not to allow plaintiff to testify on his own be-
half). “[I]t is not our job to substitute our judgment for that of
the [u]nion, even if, with the benefit of hindsight, it appears
that the union could have made a better call.” 

(ci-
tation and internal quotation marks omitted). Here, Taha does
not dispute that the union acted within its discretion when it
excluded Taha’s testimony and exhibits. Nor does he explain
why the exclusion of that evidence was irrational. As above,
answering that question hinges on what the excluded evi-
dence would have shown. But Taha gives no answer to any of
these inquiries, so we lack any basis to infer the union acted
irrationally or outside the bounds of its discretion.
10                                                 No. 19-1085

    Because Taha pleaded no factual details to support his
claim that the union irrationally compromised his JBA hear-
ing, and because he did not fill in those gaps in the district
court or this court, we see no reason to disturb the district
court’s resolution of this issue.
                               2
    Taha also failed to plead a plausible bad faith claim.
Whether a union acted in bad faith calls for a subjective in-
quiry and requires proof the union acted (or failed to act) due
to an improper motive. 

. A conclusory
allegation of bad faith conduct, without more, does not show
illegality. See 

–57. Put another way,
Taha must allege “more than a sheer possibility” that the un-
ion acted unlawfully. 

.
    But “sheer possibility” is all Taha has offered. Taha
presses only one fact to support his charge of bad faith con-
duct: Stripling and Starck discussed airline tickets before the
JBA hearing. Yet he does not allege a causal or even correla-
tive relationship between that conversation and the quality of
Stripling’s representation. Nor does he link the Strip-
ling/Starck conversation to the union’s refusal to pursue arbi-
tration. Twombly instructs plaintiffs to “nudge[] their claims
across the line from conceivable to 

.
Taha’s claims backslide from conceivable to plumb specula-
tion when he concedes: “Why the [u]nion representative folds
is not entirely clear—quid pro quo for the airline tickets, or
perhaps some other motive lurks.” Br. of Plaintiff-Appellant
Osama Taha 13, ECF No. 23. This conjecture also assumes the
union “folded” without any facts to support that allegation.
Rule 8(a)(2) requires a plaintiff to state more than raw guess-
work to survive a Rule 12(b)(6) challenge. Because Taha never
No. 19-1085                                                     11

elevates his bad faith claim from speculative to plausible, the
district court properly dismissed it.
                                B
    The district court also dismissed Taha’s complaint as time-
barred. A duty of fair representation claim is governed by a
six-month statute of limitations, Renneisen v. Am. Airlines, Inc.,

, 925 (7th Cir. 1993), which accrues “when the
claimant discovers, or in the exercise of reasonable diligence
should have discovered,” the alleged breach, Christiansen v.
APV Crepaco, Inc., 

, 914 (7th Cir. 1999). Here, the
parties dispute when Taha’s claim accrued.
    We need not answer this accrual question, however, for
we agree with the Rule 12(b)(6) grounds on which the district
court resolved this case. See, e.g., Antrim v. Burlington N., Inc.,

, 377 (7th Cir. 1988) (declining to consider timeli-
ness of unfair representation claim—even when it appeared
“unlikely that the suit is timely”—and affirming dismissal on
separate grounds). A dismissal under Rule 12(b)(6) is an ad-
judication on the merits. Davis v. Lambert, 

, 1058
(7th Cir. 2004). On the other hand, the statute of limitations
for an unfair representation claim is a non-jurisdictional af-
firmative defense. 

. There is no reason
to reach a non-jurisdictional timeliness issue when a plaintiff
cannot succeed on the merits, see Patt v. Family Health Sys.,
Inc., 

, 752 (7th Cir. 2002), so we express no opinion
on when Taha’s claims accrued.
12                                                No. 19-1085

                             III
    A complaint must state a plausible claim showing that the
pleader is entitled to relief. Taha’s second amended complaint
fails to meet this standard, so we AFFIRM.