Grover Norquist, whose conservative watchdog group Americans for Tax Reform has convinced basically every Republican running for Congress over the last decade to sign a never-raise-any-taxes pledge, told The Washington Post‘s editorial board that, to their (and, I think, the world’s) astonishment, that GOP congressmen who vote to let some or all Bush tax cuts expire would not be in violation of their sacred oath:

With a handful of exceptions, every Republican member of Congress has signed a pledge against increasing taxes. Would allowing the Bush tax cuts to expire as scheduled in 2012 violate this vow? We posed this question to Grover Norquist, its author and enforcer, and his answer was both surprising and encouraging: No.

In other words, according to Mr. Norquist’s interpretation of the Americans for Tax Reform pledge, lawmakers have the technical leeway to bring in as much as $4 trillion in new tax revenue — the cost of extending President George W. Bush’s tax cuts for another decade — without being accused of breaking their promise. “Not continuing a tax cut is not technically a tax increase,” Mr. Norquist told us. So it doesn’t violate the pledge? “We wouldn’t hold it that way,” he said.

Epic news. This makes a deal on the debt ceiling much more plausible, and should cheer progressives who want to see the biggest, most regressive tax cut in U.S. history–and by far the greatest driver of the deficit–fall by the wayside.