Last figures I saw had Obama and Clinton both raising nearly twice as much money as John McCain. Maybe this is a blessing in disguise. A lot of campaign money is given to buy "access". If you have have donated serious money to a man's campaign, he will probably answer his phone when you call. And after listening to your pitch, there is a chance that he will actually get out there and do something for you. Certainly Hillary can be swayed by money. Probably Barack as well.
How about flinty old John McCain? Not very likely. Every knows that McCain is his own man and does his own thing. So why bother to buy access to a man who isn't going to do what you ask?
Is that the reason for the lag in fund raising?