In addition, as a Justice Department lawyer, Alito argued for an expansive interpretation of presidential power. The issue resonates amid the furor over domestic spying, in which the White House has argued that the president's authority as commander in chief gave him the right to order wiretapping without warrants.
Moreover, heightened Democratic opposition is expected because he would replace Justice Sandra Day O'Connor, one of the court's swing votes on issues such as abortion rights.
There is "perceived to be more at stake in terms of the balance of power on the court on certain key issues," said Sen. John Cornyn (R-Texas), a Judiciary Committee member and a firm Alito supporter.
Noting the uncertainty over whether another Supreme Court vacancy would occur during Bush's second term, Cornyn said he thought there might be some sense among Democrats "that it's now or never, in terms of efforts to try to defeat his nominees."
Jennifer Duffy, who studies the Senate for the nonpartisan Cook Political Report, said she expected Alito to gain confirmation to the high court, but by no more than a handful of votes.
"He's going to have to make a really big mistake, or Democrats are going to have to succeed in turning him into a boogeyman, or he will be confirmed," Duffy said. "But the Democrats' efforts haven't succeeded so far, and they're running out of time."
Congressional strategists on both sides said they shared Duffy's view of the vote count. But with Republicans weakened, most recently by the influence-peddling scandal surrounding former lobbyist Jack Abramoff, some Democrats are mulling whether to try to thwart Alito's confirmation through a filibuster, a tactic in which a minority party can block a vote by refusing to end debate.
"We are more apt to filibuster now than we were two weeks ago," said one Democratic leadership aide on Capitol Hill, who requested anonymity when discussing party strategy.
That view was bolstered by comments on Sunday talk shows by Democrats on the Judiciary Committee.
Asked on "Fox News Sunday" whether she would join a filibuster of Alito's confirmation, Sen. Dianne Feinstein of California responded: "If I believed he was going to go in there and overthrow Roe ... most likely yes."
Sens. Charles E. Schumer of New York and Edward M. Kennedy of Massachusetts also said they had not ruled out a filibuster.
