SCOTUS however found:
"In today's [6/25/01] ruling, Justice David Souter, writing for the majority, said unlimited party spending would undermine the purpose of campaign finance rules. "We hold that a party's coordinated expenditures, unlike expenditures truly independent, may be restricted to minimize circumvention of contribution limits," Souter wrote."
So, clearly, a liberal majority is quite willing under what they consider to be reasonable circumstances, to restrict a freedom to spend money on political campaigns.
I don't see the ad ban in McCain Feingold to be that far a leap for them.