Photo: Win McNamee/2012 Getty Images

Political reporters and pundits lean heavily on the horse race method of coverage, which has badly hurt Mitt Romney for most of the campaign. Last night it helped him. Romney was forceful and articulate and dodged his association with almost all the most unpopular aspects of his platform. But his success at doing so was built upon two demonstrable untruths.

The most important was taxes. Romney asserted, “I cannot reduce the burden paid by high-income Americans.” Let me explain how this is untrue even by his own campaign’s accounting.

Obama badly flubbed this topic by allowing Romney to change the baseline of the discussion. Romney is promising to extend all the Bush tax cuts and refuses to accept even slightly higher revenue as part of a deficit deal. On top of that, he is proposing a huge, regressive income tax rate cut that would reduce revenue by an additional $5 trillion, but promises to make up for it by closing tax deductions. Obama directed his fire almost entirely at the additional tax cut, leaving mostly untouched, until the end, Romney’s pledge to never bargain away any of the Bush tax cuts.

Obama’s case was sound. The Tax Policy Center has shown that the stated parameters of Romney’s plan don’t add up — even under favorable assumptions, there are not enough tax deductions for the rich to close to pay for the rate cuts. Romney has disputed this and cited a series of studies that, in various ways, change the parameters of the Tax Policy Center study. Some of these studies find that it could be theoretically possible that Romney could cut rates and, by closing loopholes, do so without losing revenue or raising taxes on the middle class — if you lower the bar on who is middle class from $250,000 to $100,000, or count the repeal of Obamacare to help pay for the tax cuts, or use really wildly optimistic growth assumptions.

None of these studies back up Romney’s claim that he won’t reduce taxes on the rich. They confirm that he will reduce taxes on the rich. They merely suggest that he could make up the revenue some other way than taxing the middle class or increasing the deficit — that the economic growth will help the tax cuts for the rich pay for themselves, or that some of the lost revenue can be made up for by cutting off subsidies for the uninsured. Romney flat-out misstated his position.

The other issue was health care. Romney has promised to protect health insurance for people with preexisting conditions who maintain continuous coverage. That caveat is vital, because that right has existed since 1996. It’s a very minor protection. Phrasing his promise this way has allowed Romney to make a promise that sounds like he would keep Obamacare’s protections for people with preexisting coverage without committing himself to anything at all (except, I suppose, keeping in place a 1996 law that didn’t do much).

At the debate last night, Romney didn’t phrase his promise in this misleading-but-true fashion. He promised, “preexisting conditions are covered under my plan.” That is not true. He dropped the legalistic mumbo-jumbo that renders his promise meaningless and promised something. But his plan doesn’t do that. And his adviser Eric Fehrnstrom, asked after the debate if Romney was really promising to cover people with preexisting conditions, admitted that he isn’t. (“With respect to pre-existing conditions, what Governor Romney has said is for those with continuous coverage, he would continue to make sure that they receive their coverage.”)

Romney won the debate in no small part because he adopted a policy of simply lying about his policies. Probably the best way to understand Obama’s listless performance is that he was prepared to debate the claims Romney has been making for the entire campaign, and Romney switched up and started making different and utterly bogus ones. Obama, perhaps, was not prepared for that, and he certainly didn’t think quickly enough on his feet to adjust to it.