» Current justices | Chief justice duties | Court appointments | Special GOP sets up showdown over Alito Massachusetts senators try 'uphill' filibuster push RELATED QUICKVOTE Why do you think John Kerry wants to filibuster Samuel Alito? Conviction Politics or View Results SPECIAL REPORT YOUR E-MAIL ALERTS Supreme Court Samuel Alito or or Create Your Own WASHINGTON (CNN) -- The Senate's top Republican decided Thursday to force a showdown on Supreme Court nominee Samuel Alito early next week, with the two Democratic senators from Massachusetts pushing to block a vote. Senate Majority Leader Bill Frist filed a motion to cut off debate on the Alito nomination after his Democratic counterpart, Minority Leader Harry Reid, objected to a move by GOP leaders to schedule a final vote on his confirmation Monday afternoon. Frist's motion, which requires 60 votes under Senate rules, will come up for a vote at 4:30 p.m. Monday. If successful, senators will then vote on Alito's nomination at 11 a.m. Tuesday, with a simple majority of 51 votes needed for approval. (How a filibuster works) Frist's move came as Sen. John Kerry of Massachusetts was lobbying his Democratic colleagues to filibuster the Alito nomination -- an uphill fight, given that none of the chamber's 55 Republicans has opposed his confirmation and three Democrats are on the record supporting it. "Judge Alito's confirmation would be an ideological coup on the Supreme Court," Kerry said in a written statement. "We can't afford to see the court's swing vote, Justice Sandra Day O'Connor, replaced with a far-right ideologue like Samuel Alito." (Watch Kerry's political gamble -- :50) The White House expressed confidence that Alito's supporters had the 60 votes needed to cut off a filibuster, a maneuver allowed under Senate rules to block a vote by extending debate indefinitely. Earlier Thursday, Senate Minority Whip Dick Durbin, who is in charge of rounding up his colleagues for key votes, also played down the possibility of a filibuster, though he said no decision had been made. "One of the first responsibilities of someone in Congress is to learn how to count," the Illinois Democrat said. "Having made a count, I have come to the conclusion it is highly unlikely that a filibuster would succeed." Democrats split Two Democrats announced Thursday that they would vote for the 55-year-old Alito: Sen. Robert Byrd of West Virginia and Sen. Tim Johnson of South Dakota. Both represent states that Bush carried in the 2004 presidential election. In a speech on the Senate floor, Byrd, the longest-serving Democrat in the Senate, said he refused "simply to toe the party line when it comes to Supreme Court justices." "My considered judgment ... leads me to believe [Alito] to be an honorable man, a man who loves his country, loves his Constitution and a man who will give of his best," said Byrd, who faces re-election in November. "Can we really ask for more?" Johnson said that while he was "troubled" by some of Alito's views, "I cannot accept an argument that his views are so radical that the Senate is justified in denying his confirmation." He also said he would oppose any filibuster of the nomination. Sources close to Kerry, who lost to Bush in the 2004 race, told CNN that the senator was calling colleagues from Switzerland, where he was attending the World Economic Forum. He announced his decision to support a filibuster Wednesday at a meeting of his Democratic colleagues. The White House believes Alito's supporters have the 60 votes they need to block any filibuster, spokesman Steve Schmidt said, and suggested that Kerry's move was designed to buttress a possible 2008 presidential run. Bush said Thursday he was looking forward to an "up-or-down vote" in the Senate and praised Alito, a judge on the 3rd U.S. Circuit Court of Appeals, as a man of "character and integrity." Bush tapped Alito for the job after his White House counsel, Harriet Miers, withdrew her nomination. Republicans and the White House are pushing to have the final vote before Bush gives his State of the Union speech January 31, Senate sources have said. 'Vote of a generation' Massachusetts Sen. Ted Kennedy also said Thursday he would support a filibuster, though he described it as "an uphill climb." "This is a vote of a generation and a test of conscience," Kennedy said in a statement. "Judge Alito does not share the values of equality and justice that make this country strong. He does not deserve a place on the highest court of the land." In the floor debate of Alito's nomination, other Democrats have been highly critical of the nomination, saying he would threaten civil liberties and fail to act as a check on executive power. Sen. Patrick Leahy of Vermont, the Judiciary Committee's ranking Democrat, had supported Chief Justice John Roberts' nomination last fall. But this time, he said, "I am concerned that if we confirm this nominee it will further erode the checks and balances" between the branches of government. Kennedy told reporters that at least five Democrats are on board supporting the filibuster, and he said he expects others to join the effort. In addition to Byrd and Johnson, Democratic Sen. Ben Nelson of Nebraska has said he will support Alito. Earlier Thursday, Sen. Mary Landrieu of Louisiana said she would oppose a filibuster. With their support, and with the 55 Senate Republicans expected to oppose any filibuster, GOP leaders would need to find only one more Democrat to thwart a filibuster attempt. In May, Byrd, Nelson, Landrieu and four other Democrats joined seven Republicans in agreeing to oppose Democratic filibusters of some Bush judicial nominees and any attempt by Republican leaders to change Senate rules to end the practice, except under "extraordinary circumstances." So far, that agreement has held. The other Democrats in the group, known as the "Gang of 14," are Sens. Joe Lieberman of Connecticut, Daniel Inouye of Hawaii, Mark Pryor of Arkansas and Ken Salazar of Colorado. CNN's Ted Barrett, Dana Bash, Lisa Goddard and Ed Henry contributed to this report. Home Page Get up-to-the minute news from CNN CNN.com gives you the latest stories and video from the around the world, with in-depth coverage of U.S. news, politics, entertainment, health, crime, tech and more. Home Page Get up-to-the minute news from CNN CNN.com gives you the latest stories and video from the around the world, with in-depth coverage of U.S. news, politics, entertainment, health, crime, tech and more.