But the decision of congressional leaders to intervene in the case, which played out dramatically over Palm Sunday weekend, reflects a highly charged mix of religion and politics that critics say could have broad and unintended consequences.

"Congress's overreaching flies in the face of our entire system of checks and balances, trashes the partial sovereignty of the states, and flouts the protections our laws afford state adjudication from drive-by attacks by those disaffected with the results," says Laurence Tribe, a Harvard University law professor.

The speed and intensity of the issue surprised many on Capitol Hill. Most members had already left Washington for a two-week recess and long-planned travel overseas when doctors removed the feeding tube from a brain-damaged woman in Florida on Friday.

In an unusual move, the Senate was called back for an extraordinary session on Saturday evening, opening the door for House and Senate votes expected during early Monday morning hours. The bipartisan compromise worked out between House and Senate leaders on Saturday asks a federal court in Florida to consider the parents' claim to restore the feeding tube. President Bush said he would return to the capital to sign the bill.

Mrs. Schiavo has been diagnosed by doctors as "in a persistent vegetative state" for the past 15 years. Her husband, Michael Schiavo, says that his wife would not want to have her life extended - a view her parents reject. She left no written directive.

For many conservative activists, the Schiavo case is a proxy for expanding a pro-life agenda on everything from abortion rights to judicial nominations. "It's a real showdown with the courts," says Tony Perkins, president of the Family Research Council, who has been in continuous contact with congressional leaders and "our grass-roots across the country" on the case. "This case is important to family members of Terri Schiavo and to our country as a whole - that we not move down this path where people are forced to die," he says.

Last week, as both houses of Congress were rushing to pass resolutions on the president's FY2006 budget, GOP leaders began discussing the case. Physician lawmakers in both the House and Senate disputed the attending physicians' claims that Mrs. Schiavo was in a "persistent vegetative state."

Senate leader Bill Frist, a surgeon, said that "From a medical standpoint, I wanted to know a little bit more about the case itself," so he reviewed the 2001 tapes on which the case was based. "Scores of neurologists have come forward and said that it doesn't look like she is in a persistent vegetative state," he said last week.

GOP leaders in both houses describe this case as having to do with the "culture of life" theme expected to be central in the 2006 congressional races. "Their gamble is that the general public will be divided on the issue and will not vote on the subject come 2006, but that the Republican-base ... group of conservative Christians will remember this vote forever," says Larry Sabato, a political scientist at the University of Virginia in Charlottesville.

Meanwhile, while individual Democrats have spoken out strongly against congressional intervention in this case, their leadership, which Republicans describe as "very cooperative," has stayed out of the debate. Senate Democratic leader Harry Reid has supported "pro-life" positions, including votes against abortion rights. House Democratic leader Nancy Pelosi spoke with Speaker Dennis Hastert from her travels in Egypt.

Still, some Democrats tried to rally their party to defeat the measure. "The tragic and complicated matter is only made more difficult with congressional intervention," said Rep. Henry Waxman, ranking Democrat on the House Government Reform Committee.

Congress's move to elevate this case to federal courts comes as Republicans and Democrats are ramping up for a battle over the process for confirming judicial nominations. It also follows a bipartisan vote to move many class-action cases out of state courts, dubbed by some Republican lawmakers as "judicial hellholes," into federal courts.

The Schiavo case is already one of most extensively litigated right-to-die cases in history. Mr. Schiavo began court action to remove his wife's feeding tube in May 1998, eight year after she fell ill. Pinellas County Circuit Judge George Greer has ordered the feeding tube removed three times. In 2003, the Florida legislature passed a bill to reinsert it, a move later ruled unconstitutional, setting in motion the current legislative battle.

Should a bill on Schiavo pass the Congress and be signed by the president, as expected, the case still faces judicial review - and a ticking clock. Last week, the Supreme Court rejected without comment a House committee's emergency request to order the feeding tube reinserted while appeals were pending.

"It would appear to be the kind of legislative grandstanding that Chief Justice Rehnquist, if he were up to speed and in good health, would swat away in an instant," says Patrick Gudridge, a law professor at the University of Miami.