I’m not a big fan of the McCain-Feingold campaign finance "reform." But way back when, Barack Obama sought lay the foundations for a public funding truce for the general election, and John McCain took him up on it.

But now, things look a little different.

In a sense, McCain has the larger problem, first of all, because he lacks Obama’s fund-raising prowess and, second, because he’s one of the principal authors of a system that doesn’t really work. But when he was a fresh face, Obama seemed to want to play by McCain’s rules, at least for the rhetorical advantage, image-polishing, and attention it would give him.

McCain should relentlessly challenge Obama to live up to this "deal," but if that tack fails, he should be man enough to admit that the public financing system with which he’s identified is irretrievably broken. He and Obama both have something to lose if the "gentleman’s agreement" doesn’t hold. But McCain’s "change" can be explained (call it "spun," if you must) as a manly recognition that the ways of the political world can’t be regulated as rigidly as he’d like. He can adapt, coming up with something new (now there’s a word that’s in fashion!).

Obama, I think, has a harder time coming up with a plausible rationale for his unwillingness to keep his "pledge." Does he say that effecting change in Washington is more important than keeping his word? Does he say he never really meant it, that it was just an option his campaign was exploring in its early stages? To those who pay attention, he’ll look a little more like an ordinary politician.

The question is, how many will be paying attention?