The U.S. Senate on Wednesday begins a showdown over President Bush’s stalled judicial nominees, with the majority Republicans threatening to change Senate rules in a move that could shift the balance of power between Congress and the White House.

It was uncertain whether Bush’s fellow Republicans had the votes to prevail — or if a group of largely moderate lawmakers could find a last-ditch compromise.

This much was clear, however: if Bush gets his way, it will be easier for him to put judges on the federal bench, including the U.S. Supreme Court, without the threat of Democratic procedural roadblocks known as filibusters.

Senate Majority Leader Bill Frist, a Tennessee Republican, planned to bring up for consideration Priscilla Owen, a Texas Supreme Court justice first nominated by Bush to the 5th U.S. Circuit Court of Appeals four years ago this month.

A confirmation vote was expected on Owen late this week or next week. She was one of seven circuit court nominees blocked by Democrats in the last Congress because they were seen as too conservative. Bush renominated them after he won re-election in November.

Bush, in addressing a Republican Party gathering on Tuesday night, said, “I have a duty to nominate well-qualified men and women to the federal judiciary. I have done just that and I will continue to do so.”

“The Senate also has a duty: to promptly consider each of these nominees on the Senate floor, discuss and debate their qualifications and then give the up or down vote they deserve,” the president said.

A simple Senate majority is needed to confirm a nominee, but 60 votes are required to end a filibuster and clear the way for a confirmation vote.

While Republicans contend all judicial nominees deserve a confirmation vote, Democrats argue the filibuster must be maintained as a tool for the minority to check the power of the majority.

If Democrats again filibuster Owen, as expected, Republicans vow they would vote to ban such tactics against candidates for the circuit court or Supreme Court.

But it was uncertain if Republicans, who control 55 of the Senate’s 100 seats, could muster the needed 51 votes. A number of Republicans have voiced concern that the move could come back to haunt them in a future Democratic-led Senate with a Democratic president.

“It’s going to be close,” said Sen. Susan Collins of Maine, who is among a handful of Republicans yet to say publicly whether they would vote to abolish filibusters. “I still hope that there will be a compromise.”

Sens. John McCain, an Arizona Republican, and Ben Nelson, a Nebraska Democrat, have sought to line up six members of each party as part of a potential bipartisan deal.

Under the deal, confirmation votes would be cleared for some of Bush’s disputed nominees, but the right to block others would be preserved.

Republicans would also promise not to eliminate judicial filibusters through the end of 2006, and Democrats would vow not to use such tactics against any circuit court or Supreme Court nominee except in “extreme circumstances.”

McCain said, “I’m doing everything I can, and several like-minded people are doing the same thing. I don’t know if we will reach an agreement or not.”

© 2005 Reuters