Argument: Open primaries violate right of free association
Alexis de Tocqueville wrote in Democracy in America, and was quoted by an opponent of Open Primaries as having said: "The most natural privilege of man, next to the right of acting for himself, is that of combining his exertions with those of his fellow-creatures, and of acting in common with them. The right of association therefore appears to me almost as inalienable in its nature as the right of personal liberty. No legislator can attack it without impairing the foundations of society."
George Will. "Proposition California ensures electoral blandness." Washington Post. June 13th, 2010: "Proposition 14's purpose is to weaken and marginalize parties, traditionally the principal vehicles for voter education and mobilization. It would strip them of their core function of selecting candidates who represent the preferences of their members. It infringes the First Amendment protection of freedom of association, which includes the right of parties not to associate with candidates they do not select."