The Senate yesterday blocked the Dream Act, a bill to legalize illegal-alien students — the second major immigration bill to be stopped this year and a signal that this Congress is too stalemated to pass any bill that offers a path to citizenship for illegal aliens.

"A lot of senators concluded that from the last vote: Citizenship is not on the table anymore," said Sen. Jeff Sessions, Alabama Republican, who led the opposition to the Dream Act and who said the failure earlier this year of President Bush's broad legalization bill has fundamentally moved the debate toward the right.

Yesterday's vote was 52-44, with supporters falling eight votes shy of the 60 needed to bring the bill to the floor. Supporters said they couldn't overcome the "bigotry and hatred" that have dominated the debate over the past few months.

"This debate has changed. What has happened is there are people who are using this issue politically and creating a lot of fear," said Sen. Richard J. Durbin, the Illinois Democrat who sponsored the Dream Act. "It's about confusion, distortion, vitriol."

He said it took courage for senators to vote with him.

The Dream Act was supposed to be the least contentious part of immigration, with even Republican opponents acknowledging it applied to those with the least moral culpability in the immigration debate — those who were brought here without any say by their parents when they were children younger than 16, who have graduated from high school and who have finished or plan to complete two years of college or military service.

The bill would have given those people conditional green cards, with an eventual chance for citizenship.

But the bill fell victim to the same conflicted and complicated parliamentary maneuvering that killed the president's immigration bill earlier this year. Senate Minority Leader Mitch McConnell, Kentucky Republican, complained Democrats were shutting out his party's amendments, while other Republicans who support legalization said they didn't want to pass a bill that would only take care of one group.

"I do not think we ought to cherry-pick and take the pressure off comprehensive immigration reform," said Sen. Arlen Specter, Pennsylvania Republican.

That doesn't mean senators won't try. Several have vowed to offer a bill to legalize illegal-alien agriculture workers and create a guest-worker program for other agriculture workers. Both House and Senate lawmakers hope to pass a bill increasing the number of visas available for high-skilled science and technology workers.

Mr. Durbin, though, said yesterday's vote may cause him to have to oppose the technology bill, which would apply to what's known as the H-1B visa program.

"The people who are anxious for H-1Bs should have been standing in a chorus of support for the Dream Act," Mr. Durbin said. "There's a growing sentiment among many of us that if we are going to deal with immigration in a just, fair way, we cannot just cherry-pick the brightest people in the world to come into this country and turn our back on these young people."

Meanwhile, Republicans argue no immigration bills should pass until the federal government has proved it has sealed the border and begun enforcing laws against employers who hire illegal aliens.

In yesterday's vote, 12 Republicans joined 38 Democrats and two independents in voting to bring the bill to the floor, while eight Democrats joined 36 Republicans in opposing it.

There were some surprises among the senators who did not vote. Sen. John McCain, the Arizona Republican who is running for president and suffering among conservative primary voters for his position on immigration, did not vote, though he was in the chamber just minutes earlier for two other votes on a judicial nomination.

Three Democrats running for president — Sens. Hillary Rodham Clinton, Barack Obama and Joseph R. Biden Jr. — all voted for the act, while another, Sen Christopher J. Dodd, missed all of yesterday's votes.

In an official statement of policy the White House made clear Mr. Bush has a number of problems with the bill, including creating a "special class of illegal aliens" and offering a perpetual amnesty, rather than a one-time forgiveness.

The White House said the Dream Act could legalize felons, would allow newly legalized residents to jump the existing immigration line, and would open the system up to document fraud — all charges Republicans aimed at Mr. Bush's own bill earlier this year. Still, while he has issued frequent veto threats on a number of Democratic bills, Mr. Bush did not vow to veto this measure.