Back in '07, when McCain's campaign was foundering, he opted into
the public financing system--welfare for candidates. There is a 54
million dollar cap through August of this year, which McCain has
already exceeded.
McCain claims that he never received those funds, and therefore the
rules don't apply. But McCain used the promised funds to secure a
bank loan and the law states that anyone who uses the promises of
those loans are bound by the limits.