Forget his current lobbyist scandel, here is where McCain may end up really screwing himself. It seems that he's breaking the Federal Election Committee laws that he himself wrote! Americablog has a very simple explaination of what this is and why it is important:

When John McCain's campaign was strapped for cash John McCain opted into the campaign financing system by requesting certification that he was eligible to collect federal money. As the New Hampshire primary approached and John McCain was broke he took material advantage of the system by using the promise of matching funds to borrow money to keep his campaign afloat. And he took advantage of a rule that gives candidates who take public financing automatic ballot access on ballots in several states. (Governor Dean estimated that he spent 3 million dollars in 2004 getting on ballots in states because he had opted out of the public financing system. )

Once John McCain had taken advantage of the system by gaining ballot access and securing a campaign saving loan, he won the New Hampshire primary and became the apparent nominee of the Republican Party. He then sent a letter saying that he was opting out of the primary process and claiming that the FEC is now impotent to stop him.

If John McCain is forced to stay in the matching system he will only be allowed to spend $56 million dollars before the Republican convention in September. As of the end of January John McCain had already spent $49 million dollars meaning that today he's either close to the cap or over the amount of money he can spend during the primary.

What does it mean for John McCain? It's yet another issue where John McCain tries to legislate one way and do something completely different. In this case it has to do with campaign finance issues. As Brad Smith, the former Republican FEC commissioner noted, if McCain drops out of the system the FEC will subpoena McCain, and his staff during and their records to determine whether they violated the law. If they're found to be in violation of the law they can be fined up to $25,000 and they can be jailed for up to five years.