Already, conservatives are mobilizing against Specter, whose vote against Robert Bork's 1987 nomination to the Supreme Court they have long resented. James C. Dobson of Focus on the Family and the Concerned Women for America, which played a big role in Bush's reelection, are spearheading the campaign against Specter.

Specter won the Pennsylvania primary only because Bush and Sen. Rick Santorum (R-Pa.) helped bat down a tough challenge from Rep. Patrick J. Toomey (R-Pa.), who brandished his hard-line social and fiscal credentials. Now Santorum and Senate Majority Leader Bill Frist (R-Tenn.), both of whom may be eyeing a White House run in 2008, are treading warily, fearful of angering the right but reluctant to turn on Specter.

Specter may still be able to rescue his chances of replacing Sen. Orrin Hatch (R-Utah) as committee head. He has time to buy goodwill: The panel won't vote on him until January, after new senators are sworn in. But those new senators, such as Oklahoma's Tom Coburn and South Carolina's Jim DeMint, are fire-breathing right-wingers who make Specter look like a Massachusetts liberal. What's more, Specter, who has gobbled up political contributions from lawyers, is lukewarm on tort reform, also a priority for conservatives who want to curb suits against doctors and big business.

It would be comforting to think the infighting surrounding Specter's nomination will be duplicated on other issues, including Social Security and tax reform. Republicans have been chafing over the relentless growth of government under Bush, who lacked the guts to veto a single spending bill. Also, unlike Bush, many GOP lawmakers will be up for reelection in 2006 and are wary of opening themselves up to Democratic charges of gutting social programs. But judging by the capitulations of moderates such as Sen. John McCain (R-Ariz.) and Olympia Snowe (R-Maine) to the White House's tax-cutting zeal, it might be naive to count on a logjam.