President Bush blamed Senate Democratic leader Harry Reid on Saturday for the potentially fatal blow dealt to compromise immigration legislation.

The landmark bill, which would offer eventual citizenship to millions of illegal immigrants, fell victim Friday to internal disputes in both parties.

But Bush — echoing earlier complaints from Senate Majority Leader Bill Frist, R-Tenn. — sought to lay all the fault with Reid, D-Nev., who refused to permit votes on more than three Republican-backed amendments.

"I call on the Senate minority leader to end his blocking tactics and allow the Senate to do its work and pass a fair, effective immigration reform bill," Bush said in his weekly radio address.

Reid shot back that Bush and Frist "are flat-out wrong about what happened to the immigration bill," saying Democrats proved their commitment to a comprehensive, bipartisan measure by voting twice in favor of it.

"It was President Bush and Republicans in Congress who lacked the backbone to stand up to the extreme right wing of their party, filibustered reform twice in two days, and put partisan politics ahead of border security and immigration reform," Reid said.

Hailed as a bipartisan breakthrough earlier in the week, the immigration measure would have provided for stronger border security, regulated the future entry of foreign workers and created a complex set of regulations for the estimated 11 million immigrants in the country illegally. Officials said an estimated 9 million of them, those who could show they had been in the United States for more than two years, would eventually become eligible for citizenship under the proposal.

Faced with a major setback only months before much of the Republican-controlled Congress is up for re-election, Bush sought to give life to the issue. Speaking mostly to conservatives in his party, he said border security must be improved and enforcement within the United States enhanced.

But in a nod to business leaders who support temporary worker programs that would ensure an easy supply of low-cost labor, he spoke passionately about the need to put out the welcome mat for those from other countries.

"Immigration is an emotional issue and a vitally important one," Bush said. "At its core, immigration is the sign of a confident and successful nation."

The legislation was gridlocked as lawmakers left the Capitol on Friday for a two-week break. After bewildering political maneuvering and partisan recriminations, a key vote produced only 38 senators, all Democrats, in support — 22 short of the 60 needed.

"Politics got ahead of policy on this," Sen. Edward M. Kennedy, D-Mass., lamented.

With large public demonstrations planned over the next several days, other supporters expressed hope for its resurrection.

"We have an agreement. It's not going away," said Sen. John McCain, R-Ariz.

Sen. Arlen Specter, R-Pa., chairman of the Senate Judiciary Committee, pledged to have legislation ready for debate in the Senate within two weeks of the lawmakers' return.

Frist, though, stopped short of a commitment to bring another immigration bill to the floor by year's end. "I intend to," he said, but added it would depend on the schedule, already crowded with other legislation.

Frist had initially advanced a bill largely limited to border security, an approach adopted in earlier House-passed legislation. He then embraced Bush's concept of a broader measure including provisions relating to illegal immigrants. But in doing so, he left behind GOP conservatives, who see the measure as offering amnesty to lawbreakers.

Sen. John Cornyn of Texas and other opponents expressed frustration that Reid's tactics meant they were unable to gain votes on proposals to toughen enforcement or to leave immigration policy unchanged until the border had been made secure. Republicans as a whole, including those who favored the immigration bill, decided in advance they would cast protest votes to emphasize their opposition to Reid's maneuvering.

Democrats, meanwhile, had their own divisions, principally between Kennedy and others who favored negotiating a compromise and those who were more reluctant.

In private as well as public, Reid and Sen. Charles Schumer, D-N.Y., who heads the party's campaign effort, said they did not want to expose rank-and-file Democrats to votes that would force them to choose between border security and immigrant rights, only to wind up with legislation that would be eviscerated in future negotiations with the House.