IMPEACH BUSH

WASHINGTON, Sept. 19 — A move to give terrorism suspects the right to challenge their detentions in federal court fell short in the Senate today, even though it had majority support.

Fifty-six senators voted to cut off debate, and move forward to a vote on the bill itself, a step known as cloture. But under Senate rules, 60 votes are needed to invoke cloture.

Some supporters of the bill said they might bring it up again, although it was not clear just when. The cloture vote had been expected to fail, but the result did nothing to quell the debate over the proper balance between national security and personal liberty.

"The truth is that casting aside the time-honored protection of habeas corpus makes us more vulnerable as a nation because it leads us away from our core American values," said Senator Patrick J. Leahy, Democrat of Vermont, a co-sponsor of the measure with Senators Arlen Specter, Republican of Pennsylvania, and Christopher J. Dodd, Democrat of Connecticut. Mr. Leahy is the chairman of the Senate Judiciary Committee and Mr. Specter the committee's senior Republican; both are former prosecutors.

The legal concept of habeas corpus ("You have the body" in Latin) dates back to medieval England, and is meant to protect people from being locked up indefinitely without a court review. Last year, Congress passed and President Bush signed an act eliminating the right of habeas corpus for non-Americans who are labeled "enemy combatants" in the continuing campaign against terrorism.

Most immediately, the 2006 act affected hundreds of prisoners held at the Guantánamo Bay naval base in Cuba who the authorities say are Al Qaeda or Taliban militants. Lawmakers should not allow "some of the most brutal, vicious people in the world" to bring lawsuits, Senator Lindsey Graham, Republican of South Carolina, said in arguing against the measure.

Senator Jon Kyl, Republican of Arizona, agreed. "Never has such an unprecedented legal right been granted to a prisoner of war or detainee," he said.

The United States Supreme Court agreed in June to consider whether the act's ban on habeas corpus petitions is constitutional. The American Civil Liberties Union said today that it was heartened by the majority support for restoring the right of habeas corpus, even though the measure fell four votes short of advancing.

"Today's vote was a victory for those seeking to restore both the rule of law and our nation's Constitution," said Caroline Fredrickson, director of the union's Washington legislative office.

People for the American Way had a less cheerful perspective. "With this vote, the Senate lost a chance to restore the image of our nation as a nation of laws, a nation of justice," said Tanya Clay House, the liberal group's public policy director.

Senator Russell D. Feingold, Democrat of Wisconsin, said it was "deeply disappointing" that a Senate minority had blocked efforts to restore the right of habeas corpus. "We can and should bring terrorists to justice but we can do it without sacrificing the values upon which our nation was built," he said.

Besides Mr. Specter, five other Republican Senators supported the measure. They were Chuck Hagel of Nebraska, Richard G. Lugar of Indiana, Gordon Smith of Oregon, Olympia J. Snowe of Maine and John E. Sununu of New Hampshire. Senator Bernard Sanders, independent of Vermont, also voted for it.

Senator Joseph I. Lieberman of Connecticut, who lists himself as an independent Democrat, was the only non-Republican to vote against it. Senator Saxby Chambliss, Republican of Georgia, did not vote.