While McCain's real position is just "WAH OBAMA HAS MORE MONEY THAN ME IT'S NOT FAIR,"
what he's saying might get some play in the media. But given the current contribution limits, and the volume of donations, the idea that even a maxed out donor could exert financial influence over a candidate is pretty ludicrous. More than that, even large donation bundlers are being swamped by small donors. Obama solved the problem of the corrupting influence of money in politics by hauling in too much money, and doing so without corporate PAC money. It'd be pretty hard to raise enough money to get his attention because he's raised so much.