An extraordinary eleventh-hour maneuver by Republicans in Congress to intervene in the Terri Schiavo saga had no legal precedent and was unlikely to withstand a court challenge, congressional analysts said yesterday. In harsher words, an attorney for Schiavo's husband called the late play by lawmakers "the lowest type of political strong-arming."

A House committee issued subpoenas early yesterday demanding the appearance of Schiavo, her husband and her medical caregivers at a hearing later this month, attempting to block the court-ordered removal of Schiavo's feeding tube by invoking a federal law that prohibits harming a congressional witness.

That effort failed. Schiavo's feeding tube was removed yesterday afternoon, after a Florida judge ruled there was "no cogent reason" why the last-ditch action by Congress should invalidate years of court rulings. Later, the Florida Supreme Court denied a petition for relief filed by the U.S. House of Representatives.

Congressional leaders who have long pushed seemingly contradictory positions on states' rights and respect of marriage said they would keep fighting in Schiavo's case, with House Majority Leader Tom DeLay saying yesterday that, "the sanctity of life overshadows the sanctity of marriage." The aggressive actions were praised by conservative activists who have rallied around Schiavo's story as a touchstone for the broader right-to-life movement.

But others, including Democrats and outside congressional scholars, said Republicans had overstepped their authority and could risk political backlash. In an ABC News/Washington Post poll conducted March 10-13, an overwhelming majority of the 1,001 adults polled - 87 percent - said they would not want to be kept alive if they were in Schiavo's condition.

"This is really pushing it. I haven't seen anything like it before," said Norman J. Ornstein, an expert on Congress with the American Enterprise Institute. "If I were anybody down in Florida facing a congressional subpoena ... I would say: Go ahead, make my day. Tell me what a Congress that talks all the time about federalism is doing intervening in a state process where all the legal steps have been followed meticulously."

Florida attorney George Felos, who represented Michael Schiavo in his nearly 10-year legal battle to let his wife die as he maintains she would have wanted, called the subpoena play "nothing short of thuggery" and "the lowest type of political strong-arming."

"It was odious. It was shocking. It was disgusting. And I think all Americans should be very concerned about this," Felos said at a news conference in Pinellas Park, Fla. He said that Terri Schiavo had become a "pawn in a political football game between different elements in this country and ... nothing more than a cause for certain elements to prove their political prowess and their political power."

In Washington, Rep. Henry A. Waxman of California, the ranking Democrat on the House Government Reform Committee that issued the subpoenas, called the maneuver a "flagrant abuse of power" and said the subpoenas would be unenforceable.

"Congress is turning the Schiavo family's personal tragedy into national political farce," Waxman said in a statement. "The process was a perversion of democracy."

Congressional committees do have broad powers of investigation. The committee that issued the subpoenas, led by Virginia Republican Rep. Thomas M. Davis III, is the same committee that a day earlier forced testimony on the sensitive issue of steroids in baseball from six current and former players and Commissioner Bud Selig.

But Ornstein and Gary C. Jacobson, a political science professor who studies Congress at the University of California, San Diego, said there was no precedent for Congress intervening in an single individual's medical case. Both said there could be fallout.

"I think the [social conservative] base will like it, and everybody else will feel uncomfortable about it," Jacobson said.

Conservative groups did applaud. Wendy Wright, the senior policy director for the conservative policy group Concerned Women for America, said her group was "incredibly grateful for the swift and responsive action taken by the senators and congressmen who have placed compassion above politics."

"These are extraordinary actions - unparalleled in history - driven by a desire to save an innocent woman's life," she said.

The House subpoenas, and a less formal request for testimony from Schiavo by a Senate committee, came a day after Congress had adjourned for a two-week recess without reaching agreement on legislation that could have given federal courts jurisdiction in the lengthy fight over Schiavo's life.

In unrecorded voice votes, the House and Senate voted this week to let U.S. courts take Schiavo's case from the Florida courts. The House bill would have required federal courts to review cases involving "incapacitated" people. The narrower Senate bill would have applied only to Schiavo, and would not have required a federal court to review her case.

The two proposals could not be reconciled, though, because the House adjourned Thursday evening about an hour before the Senate bill cleared.