The Senate drove a stake Thursday through President Bush's plan to legalize millions of unlawful immigrants, likely postponing major action on immigration until after the 2008 elections.
Responding to a stinging political setback, President Bush sounded resigned to defeat.
"Legal immigration is one of the top concerns of the American people, and Congress' failure to act on it is a disappointment," Bush said after an appearance in Newport, R.I. "The American people understand the status quo is unacceptable when it comes to our immigration laws. A lot of us worked hard to see if we couldn't find common ground. It didn't work."
The bill's supporters fell 14 votes short of the 60 needed to limit debate and clear the way for final passage of the legislation, which critics assailed as offering amnesty to illegal immigrants. The vote was 46 to 53 in favor of limiting the debate.
Senators in both parties said the issue is so volatile that Congress is highly unlikely to revisit it this fall or next year, when the presidential election will increasingly dominate American politics.
A similar effort collapsed in the Congress last year, and the House has not bothered with an immigration bill this year, awaiting Senate action.
The vote was a stinging setback for Bush, who advocated the bill as an imperfect but necessary fix of current immigration practices in which many illegal immigrants use forged documents or lapsed visas to live and work in the United States.
Victory for GOP conservatives
It was a victory for Republican conservatives who strongly criticized the bill's provisions that would have established pathways to lawful status for many of the estimated 12 million illegal immigrants. They were aided by talk radio and TV hosts who repeatedly attacked the bill and urged listeners to flood Congress with calls, faxes and e-mails.
The bill would have toughened border security and instituted a new system for weeding out illegal immigrants from workplaces. It would have created a new guest-worker program and allowed millions of illegal immigrants to obtain legal status if they briefly returned home.
Bush, who has made an unusual personal push to persuade key waverers to back the bill — one of his top domestic priorities — was on the phone with senators on Thursday morning after making calls Wednesday night to argue his case, said Scott Stanzel, a White House spokesman.
Bush's allies passed a similar test Tuesday, but several senators said they simply were agreeing to let debate continue for a couple of days, and they made no promises to support the legislation on Thursday or beyond.
The immigration measure would grant legalization to the estimated 12 million unlawful immigrants if they pass background checks and pay fines and fees.
The measure survived a series of unfriendly amendments Wednesday.
Sen. Bob Menendez, D-N.J., was among those disappointed Wednesday. The Senate voted 55-40 to reject his amendment that would have made it easier for some immigrants to obtain visas for family members left behind in their home countries.
"This action does nothing to allay my concerns about the increasingly right-wing tilt to these proceedings, and it makes it more difficult to vote in favor of invoking cloture on the bill," Menendez said, referring to Thursday's crucial vote to limit debate.
While Menendez and a few other Democrats oppose the bill, the main opponents have been Bush's fellow sunbelt Republicans. GOP Sens. David Vitter of Louisiana, Jim DeMint of South Carolina and Jeff Sessions of Alabama led the charge, often backed by Texan John Cornyn.
Late Wednesday, they applauded the Senate's refusal to reject a fairly low-key amendment that, because of parliamentary rules, left leaders no choice but to halt action until Thursday's showdown vote.
"They tried to railroad this through today, but we derailed the train," DeMint said. Asked if he was poised to kill the bill Thursday, DeMint replied, "we hope to."
The bill's bipartisan supporters, including liberals such as Kennedy and conservatives such as Jon Kyl, R-Ariz., pushed hard to survive Thursday's vote. But they were frustrated by the lack of enthusiasm shown by many in the president's party.
Some noted the virtual absence throughout Wednesday's floor debate of Senate minority leader Mitch McConnell, R-Ky., who has declined to say how he would vote on the measure.
McConnell left GOP colleagues including Arlen Specter, R-Pa., to contend with the Vitter-DeMint-Sessions group, while Democrats were represented in the chamber most of the day by Majority Leader Harry Reid of Nevada.