The States themselves have no constitutionally mandated role in the great task of the 490*490 selection of Presidential and Vice-Presidential candidates. If the qualifications and eligibility of delegates to National Political Party Conventions were left to state law "each of the fifty states could establish the qualifications of its delegates to the various party conventions without regard to party policy, an obviously intolerable result." Wigoda v. Cousins, 342 F. Supp. 82, 86 (ND Ill. 1972). Such a regime could seriously undercut or indeed destroy the effectiveness of the National Party Convention as a concerted enterprise engaged in the vital process of choosing Presidential and Vice-Presidential candidates— a process which usually involves coalitions cutting across state lines.
Read the ruling here
Does the case have any relevance to the state ballot challenges?