Is Mitt Romney a guy who tells a bunch of lies, or is he a liar? That the question Jonathan Chait asks, and he winds up sort-of defending Romney, saying that his lies, many of which revolve around his effort to deny his own history, have been practical in nature. "It's Romney's bad luck that fate has dictated his only path to the presidency lies in being a huge liar," Chait says, so those lies don't tell us much about what's deep in Romney's character.
There are two problems here. The first is that Romney lies about President Obama as often as he lies about himself. It's just that when he does the former, he does it with actual squirming (if he's sitting down), the phoniest smile you've ever seen, and panic in his eyes, so it's really obvious. The second problem is that Chait's distinction applies to pretty much every political liar in history. There's always a reason why a politician lies. The biggest lies come when they get caught doing something they shouldn't have (Nixon with Watergate, Reagan with Iran-Contra, Clinton with Monica Lewinsky). They might be telling themselves, "Taking responsibility is all well and good, but it's better for the country if I get out of this scandal and continue with my duties."
In fact, saving one's own skin, whether from scandal or the displeasure of the party base, is a near-universal motivation for politicians' lies. In Romney's case, what he got caught doing wasn't trading arms for hostages or getting serviced by a young intern, but supporting abortion rights and health care reform, which to the people whose votes he's now seeking are sins even more deplorable. I'd argue that Romney's lies about Obama (see here for some ) are the worse ones, because it wasn't like some reporter backed him into a corner and he was grasping at straws to keep primary voters from hating him. He could make a critique of Obama that's just as persuasive without making things up, but he chooses not to, fairly regularly.
So is there a real meaningful difference between a politician who's a liar, and a politician who tells many lies? No—or, at least, none that will matter to us as citizens. Experience tells us that a guy who lies as a candidate will not only tend to lie just as much as a president, but will probably lie about the same kinds of things. If he's lying on the campaign trail about whether he has cheated on his wife, it's a good bet he'll end up telling us more lies about future cheating. If he's lying on the campaign trail about what his tax plan contains, it's a good be he'll end up lying to us about his tax plan when he tries to pass it, as George W. Bush did.
So the really important thing to watch out for is the guy who tells lies about policy. Which would seem to apply fairly well to Mitt Romney, whatever happens to lie deep within his heart.