WASHINGTON (Reuters) -- U.S. Supreme Court nominee Samuel Alito picked up the endorsement of a key Republican on Friday and Democrats were running out of options to block Senate confirmation of a judge they fear would tilt the court too far to the political right.

Five days of Senate Judiciary Committee consideration ended with Chairman Arlen Specter announcing his support for President George W. Bush's nomination of Alito for the high court.

The Pennsylvania Republican predicted all eight Democrats on the panel would vote against him.

"I intend to vote to support Judge Alito's nomination as associate justice of the Supreme Court," said Specter, a political moderate who supports legalized abortion.

If confirmed, Alito would replace retiring Justice Sandra Day O'Connor, a swing vote on the nine-member court on hot-button issues such as abortion.

Senate Democrats, who are scattered during a winter recess, will meet next week to discuss their strategy, an aide said.

While most of the Senate's 44 Democrats are expected to vote against Alito, none has threatened to try to mount a filibuster on the Senate floor to block him from becoming the 110th member of the nation's highest court.

"My expectation, regrettably, is that it's going to turn out to be a party-line vote," Specter said, referring to the upcoming vote by the Judiciary Committee, which has 10 Republicans and eight Democrats. The nomination must then be approved by the full 100-member Senate, which is controlled by Republicans.

Alito, a 55-year-old conservative appeals court judge, was grilled during the week about his past statements in opposition to a woman's right to an abortion but refused to give definitive answers on how he would rule if confirmed for the Supreme Court.

Democrats sceptical

Sen. Patrick Leahy of Vermont was one of several Democrats who questioned whether Alito's judicial record showed he had been too quick to back the executive branch at the expense of individuals.

"I look at how deferential he's been to law enforcement," Leahy said, referring to a case involving an unarmed 10-year-old boy shot in the back by police.

Committee members will meet on Tuesday to see if they can hold a vote on Alito, but Democrats are likely to seek a short delay. Specter had been aiming for a vote next Friday by the full Senate.

During his 2004 re-election campaign, Bush put the country on notice he would try to move the court in a more conservative direction. Bush said he would look for judges in the mold of Justices Clarence Thomas and Antonin Scalia, the court's most conservative members.

While Judiciary Committee Democrats praised Alito for his intellect, they questioned statements early in the nominee's career on abortion, as well as later rulings on civil rights.

Democrats also said they were not satisfied with Alito's responses about presidential powers, especially in light of the Bush administration's expanded domestic spying that has been conducted without warrants.

The fifth and final day of the Judiciary Committee hearing was devoted to testimony from law professors and others in the legal community, as well as pro-abortion and civil rights representatives.

Theodore Shaw, president of the NAACP's Legal Defense and Educational Fund, said he was not challenging Alito's intellect or integrity. But he added, "Our review of his record has convinced us that his confirmation to the Supreme Court would cause a substantial shift ... in a manner that would make it significantly more difficult for civil rights plaintiffs to prevail."

Anthony Kronman, a former Yale Law School dean, called Alito a "judge's judge," adding that "in no case would I say that his position falls outside the range of fair disagreement or is driven by ideology."