A document circulating among Senate Republicans and conservative legal circles in Washington, D.C., outlines the plan. "A senator would raise a point of order to close debate on a nominee," it says. "The presiding officer [Vice President Cheney] would sustain the point of order, thereby setting a new, binding precedent. The minority's appeal of the ruling could be tabled with a simple majority vote."

That process would mean that Frist would not need 60 votes to invoke cloture under Senate Rule XXII. In effect, the nuclear option would prevent filibusters of judicial nominees.

The GOP leader appears perilously close to that breaking point. In recent weeks, four moderate Republicans have criticized the nuclear option in published remarks that their offices confirmed or did not challenge on Friday. Sen. Olympia J. Snowe (Maine) told the Portland Press Herald, "I just don't see how it's going to benefit us, even in the majority, to change it to a simple majority [vote] because ultimately it could create more wedges and political wounds." Sen. Susan Collins (Maine) "doesn't think the nuclear option is a great idea," her spokeswoman, Jen Burita, said.

Sen. Lincoln D. Chafee (R.I.) has said "I'm not in favor" of the option. And Sen. John McCain (Ariz.) recently told CQ Today he would not support the option because "the Senate should not be like the House."

Meanwhile, Sen. John W. Warner (R-Va.) said in a statement Friday: "I have not reached a firm view on the matter. However, I tend to be a traditionalist, and the right of unlimited debate has been a hallmark of the Senate since its inception. Without question, though, I am strongly opposed to the use of the filibuster to block judicial nominations." He said, "I remain to be persuaded that the seriousness of the problem merits such an extraordinary solution," but "the Senate may be forced to take some action to preserve the president's Constitutional obligation to fill [court] vacancies."

Sen. Chuck Hagel (R-Neb.) also has questioned the wisdom of eliminating the minority's right to filibuster, citing times when Democrats ruled the Senate.

At least three GOP senators -- Thad Cochran (Miss.), Ted Stevens (Alaska) and John E. Sununu (N.H.) -- have declined to take public stands on the issue. Democrats hope veterans such as Cochran and Stevens, who have served in the minority, will vote to preserve the filibuster tradition even though they like Bush's nominees.

Senate Democrats, on the other hand, may suffer a defection if Frist tries the nuclear option during a filibuster of an appellate court judge. Sen. Ben Nelson (D-Neb.) did not support last year's filibusters of appellate judge nominees, his spokesman, David DiMartino, said, "But when it comes to a Supreme Court nominee, he reserves the option to do so based on the nature of the nominee."