Washington ? Unable to break Democratic filibusters against a pair of President Bush’s judicial choices, Senate Majority Leader Bill Frist on Friday proposed changing Senate rules to restrict the use of parliamentary tactics to block nominations.

President Bush, in a Rose Garden appearance at the White House, deplored the delays in seating his choices for the federal bench, saying the current Senate process was “a disgrace.”

But Democrats defended their right to oppose nominations they feel stray too far from the American mainstream and made clear that they would not allow a change in rules that would weaken that right.

It takes two-thirds of voting senators to change the rules of the Senate, and Sen. Charles Schumer, D-N.Y., said there was “not a snowball’s chance in Hades” that Frist would get that many.

“If it ain’t broke, don’t fix it,” said Democratic leader Tom Daschle, noting that the Senate had approved 124 of Bush’s 126 judicial nominations that have reached the Senate floor.

Frist, R-Tenn., said changes in the rules that have governed the Senate the past 28 years were the only way to resolve an issue that has disrupted other Senate business and intensified partisan discord in the body.

Democrats, Frist said, were “breaking with Senate traditions that we have had the last 200 years. We are witnessing unprecedented obstructionism.” Other Republicans have suggested more drastic steps, including lawsuits, to contest the use of filibusters on nominees.

The dispute has come to a head over the Democrats’ thus-far successful efforts to block the nominations of Michael Estrada to the U.S. Court of Appeals for the District of Columbia and of Priscilla Owen to the 5th U.S. Circuit Court of Appeals in New Orleans.

Under current Senate rules, it takes 60 votes to end a filibuster blocking final action on legislation or a nomination. Republicans have failed to reach that number in six cloture votes on Estrada and two on Owen, both opposed by Democrats for what they say is their conservative judicial activism.

Republicans and their allies argued that the Constitution only mentions a few cases requiring more than a simple majority for passage, including treaty ratifications, overriding presidential vetoes, the impeachment of a president, constitutional amendments or expulsion of a member.