The Associated Press is reporting, on the CNN Web site, that the proposed comprehensive immigration reform bill has been withdrawn in the Senate, essentially killing the bill for now. Excerpts:

WASHINGTON (AP) — A broad immigration bill to legalize millions of people unlawfully in the United States failed a crucial test vote in the Senate Thursday, a stunning setback that could spell its defeat for the year.

The vote was 45-50 against limiting debate on the bill, 15 short of the 60 that the bill’s supporters needed to prevail. Most Republicans voted to block Democrats’ efforts to bring the bill to a final vote.

The legislation, which had been endorsed by President Bush, would tighten borders, institute a new system to prevent employers from hiring undocumented workers and give as many as 12 million illegal immigrants a pathway to legal status.

Senate Majority Harry Reid, D-Nevada, who had made no secret of his distaste for parts of the bill, said he would withdraw it but keep working toward eventual passage.

“I, even though disappointed, look forward to passing this bill,” Reid said. But he said he needs help from the White House.

“This is the president’s bill,” Reid said. “… We can’t do it alone over here. We need some help.”

Most Republicans voted against ending debate, saying they needed more time to make the bill tougher with tighter border security measures and a more arduous legalization process for unlawful immigrants.

All but a handful of Democrats supported the move, but they, too, were holding their noses at provisions of the bill. Many of them argued it makes second-class citizens of a new crop of temporary workers and rips apart families by prioritizing employability over blood ties in future immigration.

Still, they had argued that the measure, on balance, was worth advancing.

“We can all find different aspects of this legislation that we differ with,” said Sen. Edward M. Kennedy of Massachusetts, the leading Democratic architect of the bill.