When it comes to tax policy, Mitt Romney is not merely a spinner, an equivocator or a run-of-the-mill dissembler. He's a liar. Hyperbolic and overwrought as that label seems, it is, alas, the only accurate description for someone who would, in February, promote a proposal to cut taxes "on everyone across the country by 20 percent, including the top 1 percent" and then appear at an October debate and insist that the very same proposal "will not reduce the taxes paid by high-income Americans."

For the most part, analyzing such hideous dishonesty is where political reporting has started and stopped. How big a liar is Romney? Was he lying in the first statement or the second one? These are, no doubt, important questions — and to answer but one of them, it's obvious Romney was lying in the most recent one. As the nonpartisan Tax Policy Center reported, the Republican nominee's proposal, if enacted, would "result in a net tax cut for high-income tax payers and a net tax increase for lower- and/or middle-income taxpayers."

However, critical as such short-term fact checking is, it misses the much bigger news embedded in all the subterfuge. In short, it misses the genuinely mind-boggling fact that a Republican nominee for president is now campaigning for president on a promise to not cut taxes on the wealthy.

Looked at in a historical context, this could be nothing short of a much-needed, come-full-circle moment for the Republican Party.

That circle began more than a quarter century ago, when, in the midst of his push to raise taxes, President Ronald Reagan railed on "unproductive tax loopholes that allow some of the truly wealthy to avoid paying their fair share" and criticized a system that "made it possible for millionaires to pay nothing, while a bus driver was paying ten percent of his salary."

Unfortunately, since then, the GOP reoriented itself around a destructive anti-tax theology.

In a matter of a few decades, the national debt  predictably exploded as the party's orthodoxy went from "read my lips, no new taxes" (George H.W. Bush) to "if you raise taxes on these so-called rich, you're really raising taxes on the job creators" (George W. Bush) to recent years' pervasive Republican rhetoric about so-called "makers" and "takers." Yet now, suddenly, Romney is closing the rhetorical loop, repeatedly claiming during the first presidential debate that he will refuse to support any new tax cuts for the wealthy.

Of course, based on his proposal's granular details, a President Romney will almost certainly try to cut taxes for his fellow 1-percenters. Thus, it's easy to dismiss his debate statements as just unimportant campaign rhetoric representing nothing more than political expediency. But, then, Romney's lying actually underscores the potentially deeper significance of this moment. It shows even some leaders of the trickle-down party recognize that voter hostility to plutocratic tax proposals has grown (rightly) intense — so intense, in fact, that GOP leaders know their party must try to publicly disown the trickle-down image, to the point of lying about their true agenda. And here's the thing: eventually, such brand reinvention efforts often sow the seeds of more genuine changes in policy positions.

None of this means Romney is some brave hero. It merely means he is a politician who sees an America that finally recognizes how much its tax system is skewed toward the wealthy. In such a country, expedience is thankfully no longer synonymous with anti-tax demagoguery. It is, instead, congruent with a more rational rhetorical posture on tax fairness.

Coming during a fiscal crisis, that larger political shift, so perfectly reflected in Romney's lying, should be viewed as a promising development.