WASHINGTON -- Sen. Arlen Specter, the canny old fox of Pennsylvania politics, got carried away last Wednesday in the flush of an easy fifth-term victory and revealed too much of what he really thinks. He clearly imposed a litmus test requiring support of the Roe v. Wade abortion decision for Supreme Court nominees at a time when Chief Justice William Rehnquist is gravely ill. Specter committed a rare political blunder that endangers his lifetime goal of becoming chairman of the Senate Judiciary Committee.

 To correct Specter's monumental mistake, his staff Thursday put out a news release trying to contradict the senator's undeniable advocacy of a litmus test. Actually, the brief statement repeated Specter's warning of filibusters against President Bush's judges and did not pledge unqualified support for any nominee sent down by the White House. Furthermore, the sincerity of Specter's retreat was undermined when he said he had issued the statement at the urging of the conservative senator from Pennsylvania, Rick Santorum.

 Assuming that Specter cannot and will not make a flat commitment of support, the prospect of his imminent chairmanship poses tests for two ambitious Republicans. Will Senate Majority Leader Bill Frist, eyeing the White House, marshal his power to block Specter's ascension? Will Senate Republican Conference Chairman Santorum, after alienating his base by backing Specter against serious conservative opposition in this year's Pennsylvania primary, turn against his colleague?

 That challenge from Rep. Pat Toomey threatened to end Specter's long political dance in which he has worn the Republican label while wooing left-wing pressure groups. Specter survived because of aggressive support from President Bush as well as Santorum, who were inflexibly backing any incumbent Republican. No sooner had Specter been narrowly nominated than he turned leftward, declaring his independence from Bush and refusing to help two GOP congressional challengers in Pennsylvania who had a chance to win but went down to defeat.

 His easy victory Tuesday, while Bush was losing the state, apparently was too sweet for the 74-year-old senator to contain himself. In his post-election press conference, as reported by the Associated Press, he declared: "When you talk about judges who would change the right of a woman to choose, overturn Roe v. Wade, that is unlikely." He warned the president of facing filibusters, apparently without help from Chairman Specter. That was enough to inspire thousands of e-mails and telephone calls protesting Specter as chairman into the offices of Frist, Santorum and other senators.

 The Republican base would have been even more infuriated to read the full press conference transcript confirming Specter's litmus test: "I have said that bluntly during the course of the campaign and before. When the [Philadelphia] Inquirer endorsed me, they quoted my statement that Roe v. Wade was inviolate." He suggested that "nobody can be confirmed" who does not accept abortion rights. Thus, Specter's and John Kerry's positions are indistinguishable.

 Specter is in line to become chairman because Republican chairman term limits are forcing out Sen. Orrin Hatch of Utah. Sen. Chuck Grassley, an Iowa conservative and a rare non-lawyer on Judiciary, is ahead of Specter in seniority but wants to keep his Finance Committee chairmanship.

 That puts Frist, who has been criticized for his management of the judicial confirmation debacle, on the spot. He is considering asking the full Republican Conference to waive term limits for Hatch. The majority leader also may let Hatch keep his chairmanship temporarily to handle any immediate Supreme Court vacancy. Frist could mobilize a majority of the Judiciary committee's expected 11 Republicans in the new Congress to breach seniority and bump Specter.

 Santorum's situation is sensitive. With a potentially difficult re-election looming in 2006 against Democratic State Treasurer Barbara Hafer (a former Specter Republican), he does not want to alienate Specter. That explains Santorum's effort to get Specter to back down from his litmus test in Thursday's statement.

 In truth, Specter cannot really repudiate what he said. His modified stand only pledged to guarantee "prompt action" by the committee, not to actively support any Bush nominee. The test is whether the Republican establishment will tolerate a Judiciary chairman who opposes the will of voters who gave George W. Bush a second term and continued Republican control of Congress based on him favoring traditional values.