Appeal from the United States District Court for the Southern District of Illinois. No. 07 C 94-David R. Herndon, Chief Judge.
The opinion of the court was delivered by: Ripple, Circuit Judge.
Before RIPPLE, KANNE and TINDER, Circuit Judges.
Ronald Smart brought this action asserting state-law claims against the International Brotherhood of Electrical Workers, Local 702 ("IBEW"), its counsel, Christopher Grant, and Mr. Grant's law firm, Schuchat, Cook & Werner. The district court granted the defendants' motion to dismiss. We now affirm in part and reverse and remand in part the judgment of the district court.
Mr. Smart is the sole proprietor of Paschall Electric, a non-union company. In 2003, Mr. Smart contracted to perform electrical work for the construction of a sports complex. He alleges that, after he entered into the con-tract, the IBEW coerced the owner of the sports complex to terminate his relationship with Mr. Smart; specifically, Mr. Smart alleges that the IBEW threatened to withhold services and otherwise to shut down the building project if the owner did not employ union workers instead of Mr. Smart. According to the complaint, the owner fired Mr. Smart and hired a company affiliated with the IBEW to complete the work on the project.
B. District Court Proceedings
In response to the termination of Paschall Electric's services, Mr. Smart filed the present action in the United States District Court for the Southern District of Illinois. Mr. Smart alleged that the IBEW's coercive tactics violated the Illinois Antitrust Act, 740 ILCS 10/3. Mr. Smart also brought two additional claims. The first, a claim for unwarranted prosecution, was brought against the IBEW, Mr. Grant and Schuchat, Cook & Werner. The second, a claim for legal malpractice, was brought against Mr. Grant and his firm. At the heart of these claims were earlier legal actions by the IBEW to recover employee contributions to a fringe benefit fund associated with a collective bargaining agreement ("CBA").*fn1
The defendants moved to dismiss Mr. Smart's complaint on the grounds that: Mr. Smart's claims were preempted by the National Labor Relations Act ("NLRA"); they were barred by judicial estoppel; and they failed to state a claim upon which relief could be granted. The district court granted the motion. It determined that Mr. Smart's state antitrust claim was preempted by the NLRA. With respect to the common law claims, the court held that Mr. Smart had pleaded himself out of court. Turning first to the malpractice claim, the court noted that "a legal malpractice claim can only be brought by a plaintiff against his former attorney, not against an attorney or law firm that has never represented the plaintiff . . . ." Smart v. Int'l Bhd. of Elec. Workers, Local 702, No. 07-cv-94-DRH, 2007 WL 4259972, at *4 (S.D. Ill. Dec. 3, 2007). Concerning the "unwarranted" prosecution claim,*fn2 the court observed that, in order to prevail on this claim, Mr. Smart had to establish that he had prevailed in the underlying litigation. However, the court observed that none of the previous legal actions mentioned in Mr. Smart's complaint or in the IBEW's motion to dismiss were terminated in his favor. Consequently, the *fn3 district court dismissed both the malpractice claim and the unwarranted prosecution claim with prejudice. Mr. Smart timely appealed.
Before turning to the merits of Mr. Smart's claims, we must address a threshold issue: whether the district court had subject matter jurisdiction over Mr. Smart's claims. Federal district courts are courts of limited jurisdiction; "[t]hey possess only that power authorized by Constitution and statute." Exxon Mobil Corp. v. Allapattah Servs., Inc., 545 U.S. 546, 552 (7th Cir. 2005) (quoting Kokkonen v. Guardian Life Ins. Co. of America, 511 U.S. 375, 377 (1994)). Congress has conferred subject matter jurisdiction on the district courts only in cases that raise a federal question and cases in which there is diversity of citizenship among the parties. See 28 U.S.C. §§ 1331-32. Unless Mr. Smart's complaint falls into one of these two categories, we must dismiss the action for want of jurisdiction.
Turning first to the possibility that the complaint falls within the court's diversity jurisdiction, we note that Mr. Smart, as the party seeking to invoke federal juris-diction, bears the burden of demonstrating that the requirements for diversity are met. See Pollution Control Indus. of America, Inc. v. Van Gundy, 21 F.3d 152, 155 (7th Cir. 1994). Specifically, Mr. Smart must establish "complete diversity," "meaning that no plaintiff may be from the same state as any defendant." Hart v. Fedex Ground Package Sys., Inc., 457 F.3d 675, 676 (7th Cir. 2006); McCready v. eBay, Inc., 453 F.3d 882, 891 (7th Cir. 2006). However, neither Mr. Smart's complaint in the district court nor his brief to this court suggests that this requirement has been met. Quite the contrary, Mr. Smart, an Illinois citizen, asserts that one of the defendants is an Illinois law firm, which likely has partners who are Illinois citizens. See Cosgrove v. Bartolotta, 150 F.3d 729, 731 (7th Cir. 1998) ("The citizen-ship of a partnership is the citizenship of ...