applies to both GMR and its attorneys, who “stand on the same legal footing” as their clients. See Hoai v. Vo, 935 F.2d 308, 313 n. 5 (D.C.Cir.1991). Carlson also relies on the Supreme Court’s decision in Connecticut v. Doehr, 501 U.S. 1, 111 S.Ct. 2105, 115 L.Ed.2d 1 (1991). Like Lugar, Doehr concerned a state statute that authorized prejudgment attachment without prior notice or hearing. Id. at 4, 111 S.Ct. 2105. The Court did not, however, consider whether the private party was a state actor. Doehr offers no guidance here. The district court correctly applied this court’s § 1983 case law when rejecting Carlson’s claim. Finding private parties liable as state actors, this court has required joint action or conspiracy with state authorities. See Wickersham, 481 F.3d at 595, 599 (<HOLDING>); DuBose v. Kelly, 187 F.3d 999, 1003 (8th
holding that the state police is a state agency holding that a state agency created under state law was a state actor holding that a private air show is a state actor when its president is the final arbiter of what constituted unwanted protest and directs whom police arrest holding that establishing the existence of an understanding among private parties and state actors for  1983 conspiracy purposes is really nothing more than another way to show state action by alleging a private partys connection to a state actor holding that amtrak was a state actor