The particulars of what Barack Obama actually "pledged" to do on public financing notwithstanding, it's pretty clear that what coverage there has been of this issue assumes it's an ironclad pledge. Obviously, it would be of great benefit to Obama to opt out of the system, because as of now it appears he'd be likely to raise far more money than John McCain. So how can he opt out and still save face? The answer is: 527s. No, I don't mean that he should encourage people to organize 527s on his behalf. But he can use the very well-funded Republican 527s as the lever to enable him to opt out. The argument would go something like this: "I said I would 'aggressively pursue an agreement to preserve a publicly financed election' with my Republican opponent. And I'm happy to have our two campaigns sit down and see if there is a way to make the debate between me and John McCain, within the publicly financed system. But as long as there are 'independent' Republican groups out there planning on spending hundreds of millions of dollars attacking me, it would be pretty foolish to lock myself into a spending limit that makes it impossible to respond. So I ask Senator McCain: Can you call off the right-wing hit squad? If you can do that, I'll be only too happy to say we should both accept public financing. But if you can't, I'm not going to sign away my ability to compete." McCain would squawk, of course, but the real question is whether it would be enough to satisfy the press. And it just might -- at least enough to shorten the issue's life. It would also have the benefit of beginning a discussion on all the nasty, nasty stuff that will be coming at Obama from the right, and what kind of responsibility McCain bears for what is going to be done on his behalf. -- Paul Waldman