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“And when you think about what we've gone through over the last couple of months -- a devastating hurricane, and now one of the worst tragedies in our memory -- the country deserves folks to be willing to compromise on behalf of the greater good, and not tangle themselves up in a whole bunch of ideological positions that don’t make much sense.”

-- President Obama at a press conference telling reporters why Republican House members should accept his proposal for higher tax rates.

The biggest thing that happened Wednesday in the “fiscal cliff” battle wasn’t President Obama using the Connecticut school shootings to bash Republicans on taxes.

It wasn’t the announcement by the head of the IRS that as many as 100 million taxpayers wouldn’t be able to file their returns on time if there is no deal.

It wasn’t even the latest veto threat from Obama.

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It was the ruling by Americans for Tax Reform – the group led by the much maligned Grover Norquist – that a vote to extend current tax rates for most, but not all, taxpayers was not the same as voting to increase taxes.

At the outset of this lamest of lame ducks, the establishment press was all abuzz about which moderate Republican was saying disparaging things about the “Taxpayer Protection Pledge” that has become essentially mandatory for any Republican primary candidate to sign. The essence of the pledge is that the signatory is vowing to his or her would-be constituents to never vote to increase taxes.

The assumption on the left and in the press was that Norquist’s group would treat any tax deal that didn’t extend the sun setting Bush-era tax rates for everyone would as a violation of the pledge. This was an exciting idea to the Obama Democrats who foresaw a vicious battle setting up devastating primary fights in 2014 and eventually the nullification of the Republican line on taxes.

But on Wednesday, Norquist did what his detractors did not expect and declared that extending current tax rates for some but not for others was not the same as raising taxes. Since all income taxes are set to rise in 12 days, failing to prevent some increases is not the same as voting to increase them.

The verdict was passed on a proposal from House Speaker John Boehner, set for a vote today, in which current rates would be extended on all those earning less than $1 million. There is no language in the plan to increase anyone’s taxes.

This is why conservatives opposed the original Bush-era idea of making the tax rates temporary: Automatic rate increases provide a tax pledge loophole.

While the belief on the left was that Norquist himself would be the one reading Republicans out of the party if anyone’s rates rose, the truth is that it would have been primary challengers doing that work. But they might have been doing it armed with a broken promise. Wednesday’s verdict from Americans for Tax Reform makes that task much harder for primary challengers. While they can say they think a vote that extends some but not all tax rates is bad policy, they will lack the potent attack of a broken promise.

There are many conservatives who hold that this is legalistic mumbo-jumbo and that carving out anyone from a tax rate extension is the same as raising their taxes. But with Norquist’s blessing, Boehner’s “Plan B” becomes a potent new weapon in the GOP’s battle with Obama over taxes.

Since it is far too late to strike a big compromise that would substantially reduce deficits or reform taxes, the primary objective for the GOP has become to preserve the lower rates for as many Americans as possible and, most critically, win spending cuts in exchange for a looming request for an increase in the federal borrowing limit.

Today’s vote on “Plan B” will test the durability of Republican unity, but if Boehner gets enough support to pass this package on a party-line vote, he has the chance to turn up the heat on Obama.

Obama has vowed that he will veto the plan, but as the clock runs out will he be willing to hold the line? Will Senate Democrats?

What if the threshold was $750,000? $500,000? What if small business were exempted?

If Republicans can start passing compromise legislation it will become increasingly hard for Obama to argue that he has to force the nation over the cliff with a veto in order to prove his point about tax rates.

If Republicans have wiggle room on taxes, Obama will find himself on defense for spending, the debt limit, welfare programs and more.

And Now, A Word From Charles

" I think the president invoking the massacre of children to say the Republicans need to accept his terms of surrender in the negotiations is not just a non-sequitur.  I think it's a sacrilege.  It is of a piece with the tone of the news conference. This is the way he conducts them generally, in which is he is excessively self-righteous.  He talks about the other side being unprincipled, not interested in the national interest, slaves of ideology which he says makes no sense and, as you mention, invested in opposing him.  To the point they are willing to let the country suffer.  So it's a combination of self-righteousness and narcissism.”

-- Charles Krauthammer on “Special Report with Bret Baier.”

Chris Stirewalt is digital politics editor for Fox News, and his POWER PLAY column appears Monday-Friday on FoxNews.com. Catch Chris Live online daily at 11:30amET  at  http:live.foxnews.com.