During this year’s Republican Convention, I hopped a cab from Tampa to St. Petersburg, where my old acquaintance Grover Norquist, the Republican anti-tax activist, was giving a speech at the University of South Florida. In 2004 and 2005, I spent quite a bit of time with Norquist, working on a lengthy Profile that described him as the “ringleader, visionary, and enforcer” of the conservative coalition. After the piece was published, I didn’t see him often in person, but when I got to the St. Pete campus he didn’t appear to have changed much. He was wearing his usual blue suit. His beard was still red, if perhaps a little grayer around the edges. And he was making many of the same lame jokes, such as the one in which he says he was born in Massachusetts “before emigrating to America.”

Grover—almost nobody in Washington uses his surname—was in fine fettle. He talked a bit about the upcoming Presidential election, describing it as a “jump ball,” but his main topic was the historic realignment of American politics, at the local and national levels, into two strictly divided and mutually antagonistic movements: one focussed around the pursuit of lower taxes, less spending, and less regulation; the other aligned—in his telling—around higher taxes, more spending, and more regulation. “We finally have two parties that stand for something, as opposed to regional parties,” he said. “We have a real test of what works and what doesn’t.”

In the editorial columns of serious publications, this one included, it is generally held that the demise of bipartisanship is a disaster for the country. Norquist, who used to keep a bust of Lenin in his home and who sometimes refers to businessmen as “corporate pukes,” revels in an age of ideological purity. Since his early days as a Reaganite insurgent in the College Republicans, he has been working to purge the G.O.P. of moderates and free thinkers—folks like George H. W. Bush, John McCain, and the late Warren Rudman. “The structures are not going to change,” he went on. “This is the next twenty-five or fifty years of American politics.”

Norquist may yet be proved right. Three weeks after a Presidential election in which a weak Republican candidate facing a popular incumbent received forty-seven per cent of the vote, it is far too early to proclaim the death of regimented, parliamentary-style parties and the arrival of a new era of moderation and coöperation. When the fiscal cliff negotiations get serious, the Republicans, particularly those in the House, may yet revert to the scorched-earth tactics that they adopted during President Obama’s first term, daring him to go over the cliff and allow all the Bush tax cuts to lapse. (As I’ve said before, I don’t think such an outcome would necessarily be disastrous. Far from it.)

For now, though, the G.O.P. ultras are on the defensive, and none is more besieged than Norquist. To an extent that he can never have imagined on that summer day in Florida, he has become a target for Republicans seeking to do a deal with the President and, simultaneously, to shift their party to the center. What began as a few dissidents questioning the pledge not to raise taxes that Norquist has championed over the past two decades—a pledge the vast majority of Republicans in both chambers have signed—is threatening to turn into something bigger: a substantive shift in policy, and a symbolic torching of outdated dogmas, with Grover on the top of the bonfire.

His troubles began the day after the election, when Speaker Boehner indicated that he was amenable to raising tax revenues, if not tax rates—a statement that seemed to open the wary for an agreement that eliminated some of the loopholes and deductions that wealthy taxpayers enjoy. However such a deal was structured, it would almost certainly violate Norquist’s pledge, which commits its signatories to “oppose any and all efforts to increase the marginal income tax rates,” and also to “oppose any net reduction or elimination of deductions and credits, unless matched dollar for dollar by further reducing tax rates.”

Things got worse for Grover, and for his lobbying group, Americans for Tax Reform, when several Republican senators openly questioned his influence. Georgia’s Saxby Chambliss said, ‘I’m frankly not concerned about the Norquist pledge.” John McCain noted, “Fewer, and fewer people are signing this, quote, pledge.” Still, at the start of last week, Norquist was confident enough to tell a conservative think tank, “The R’s are holding.” Asked about his critics, he said they didn’t represent the party’s leadership in the House or the Senate, which, he insisted, were sticking to the pledge.

If Grover was hoping to catch a break over the Thanksgiving weekend, he was to be disappointed. On Friday, Senator Chambliss returned to the offensive, telling a Georgia radio station that he cared a lot more about the United States “than I do about Grover Norquist… I’m willing to do the right thing and let the political consequences take care of themselves.” On Sunday’s talk shows, the pledge got yet another downgrade—two, actually. Appearing on ABC’s “This Week with George Stephanopoulos,” Senator Lindsey Graham said, “I will violate the pledge” as long as “Democrats will do entitlement reform.” On NBC’s “Meet the Press,” the Long Island congressman Peter King went a step further, suggesting that a pledge signed in the past didn’t even apply today. “For instance, if I were in Congress in 1941, I would have signed a declaration of war against Japan,” King said. “I’m not going to attack Japan today. The world has changed, and the economic situation is different.”

On Monday morning, Norquist tried, once again downplayed the G.O.P. rejections of his pledge. Appearing on CNN’s “Starting Point,” he said, “No Republican has voted for a tax increase. We’ve got some people discussing impure thoughts on national television.” Many of his critics, he correctly pointed out, had been in favor of raising tax revenues during the 2011 debt-ceiling talks. “And during the debt ceiling, we cut spending, we didn’t raise taxes. So other Republicans didn’t listen to Peter King or these others.”

That’s true, but it isn’t just King and Lindsey Graham who are openly challenging Norquist’s position. At about the same time that he was gabbing on CNN, Eric Cantor, the number-two ranked Republican in the House, was appearing on MSNBC’s “Morning Joe,” where he suggested that he, too, might be willing to ignore Norquist’s pledge and do a tax-raising deal with the White House. “When I go to the constituents that have reëlected me, it’s not about that pledge,” Cantor said. “It really is about trying to solve problems. Boehner went to the White House ten days ago and said Republicans are willing to put revenues on the table. That was a big move… And we said we’re willing to do that to fix problems, to respond to the electorate that reëlected this President.”

Cantor, or course, is one of the G.O.P. firebrands who wrecked the 2010 efforts to forge a compromise involving revenue increases and spending cuts. In publicly backing Boehner’s new overture, he was careful to burnish his conservative credentials by opposing any increase in tax rates and by calling on President Obama to rein in entitlement spending. But he did indicate a willingness to support a compromise that would raise new revenues—albeit one that the White House has already publicly rejected on the grounds that it wouldn’t raise enough revenues.