Here is an excerpt from this interview at National Review Online with Sen McCain:

Ponnuru: Campaign-finance reform: Is McCain-Feingold the first step? Is there an unfinished agenda here?
Sen. McCain: I think that we need to give this law a chance to work. And there are aspects of it that are being tested in the courts. So I don’t envision any new legislation. I will say that we need to act as regards to the 527s which are a violation of the ’74 law. And 501(c)s, I believe have every right to lay out their agenda. The 527 which is designed to affect the outcome of an election, clearly, in my view should go under campaign-finance limits — contribution limits.