"If they bring a knife to the fight, we bring a gun."

Is it okay for Obama to say that? If not, why not?

McCain supporters see something to exploit, and the angle is — watch for this meme — what if McCain had said that?

Well, of course, if you say something that resonates with the opinion we already have of you, we will comment on it one way, and if you say something that seems out of character, we take a different tack. So if a warmonger laughs about a bomb, we say one thing. If a peacenik laughs about a bomb, we say another. Both are attacked, and rightly so.

But Obama — is he a peacenik? — didn't laugh about a bomb. He used a figure of speech. (Actually, he amped up the old figure of speech don't bring a knife to a gun fight.)

Figures of speech matter a bit — they offer some insight. But in this case, I was glad to see Obama show some grit and fighting spirit. I worry that he's bland and effete. I worry that he's a peacenik. So — as someone who is committed to neither candidate — I welcomed the remark. I want him toughened up.

A better angle for McCain supporters: Bring a knife to the fight? Bring a gun? Obama runs away from a fight!

There's also the notion that Obama is supposedly represents a "new politics" that precludes tough fighting. Ben Smith writes:

"Why is Barack Obama so negative? In the last 24 hours, he’s completely abandoned his campaign’s call for ‘new politics,’ equating the election to a ‘brawl’ and promising to ‘bring a gun,' " said the RNC's Alex Conant.

Obama doesn't actually use the phrase "new politics" a lot, and this is a box that the Clinton campaign tried, and failed, to keep him in last year, when it emerged early that he was happy to throw punches, and even to start fistfights, sending, for instance, the first negative mail to hit in Iowa last fall.

Obama never paid much of a price for his willingness to go negative. He also, to be fair, never promised that he wouldn't attack, and indeed often promised to be tougher than past Democrats, and bragged of his Chicago training.

Obama would be crazy to avoid fights or to allow himself to be defined as a gentle sweetheart who won't say anything mean.