Wouldn't the proper thing to do be to wait until the FEC were to issue a specific fine or ruling against FR in order to challenge the law in court.
the point is - does it have to come to that? are you willing to trust that we have 5 SCOTUS votes to stop something like this?
How about simply use a filter to replace all mention of "McCain" or "Obama" with "McCensor" and "OtherGuy"? I think you can still talk politics if you don't mention the candidates in question.