FEC Commissioner Michael Toner and Bob Bauer have written this Roll Call oped (paid subscription required), which begins: “For the second consecutive election cycle, the McCain-Feingold campaign finance law will prohibit certain political ads from running during the last 60 days before Congressional elections. These are ads that refer to a federal candidate, are paid for out of a corporation or union’s general treasury funds and are broadcast to the candidate’s voters. Nothing more than the mere mention of a candidate is required for the ban to apply. No corporation is too small, or its purposes so educational or charitable, that it is excused from this law.” Bob offers additional thoughts on the corporate PAC requirement here.