In Democratic Party of United States v. Wisconsin ex rel. La Follette, 450 U.S. 107, 120-24, 101 S.Ct. 1010, 67 L.Ed.2d 82 (1981), the Court invalidated Wisconsin's selection of its presidential delegation by open primary because it conflicted with the national Democratic Party's rules for seating delegates and thus infringed the national party's associational rights. The Court did not consider the constitutionality of state open primaries generally - except to observe that "the Wisconsin Supreme Court may well [have] be[en] correct" to uphold the Wisconsin open primary law as constitutionally valid. Id. at 121, 101 S.Ct. 1010.