ASHINGTON - Democrats were elated, Republicans furious, but the two sides shared this uneasiness: their dread that lawmakers could be called upon to decide whether Al Gore or George W. Bush is the next president.
Congress has not had to settle such a dispute since the Rutherford B. Hayes-Samuel J. Tilden race in 1876. Even with that, congressional aides said, there are few direct precedents to guide the House and Senate if, as now seems possible, Florida submits competing slates of electors to the Electoral College.
That scenario loomed larger after the Florida Supreme Court yesterday ordered an immediate, manual recount of thousands of disputed ballots across the state.
Florida Republican Representative Clay Shaw said that there have been no planning or strategy sessions yet among rank-and-file Republicans in Congress on the issue.
''It's certainly moving closer,'' Shaw said. ''I would have invested in the lottery'' before betting on this. ''Now it does seem to be in the realm of possibility.''
There is still ardent hope Congress can avoid having to act.
''I hope that it won't come to that. I would hope that they would count the votes in accordance with the court's decision, and whoever wins, wins. That's the way in this country we decide the election,'' said Representative Martin T. Meehan, a Lowell Democrat.
Yesterday's Florida Supreme Court decision came against a Dec. 18 deadline for the Electoral College to vote. The Republican-controlled Florida Legislature held a special session yesterday and is expected to appoint electors next week loyal to Bush. If Gore wins a recount, there could be two slates of electors.
''Now that the state's highest court has spoken, Americans can finally determine how the citizens of Florida voted on election day, and which candidate truly won the presidency,'' House Democratic leader Dick Gephardt of Missouri and Senate Democratic leader Tom Daschle of South Dakota said in a joint statement.
Daschle watched the decision in his Senate office, remarking after the Supreme Court clerk spoke, ''This is unbelievable,'' a staff member said. He then walked across the Capitol to a scheduled meeting with Gephardt and the White House chief of staff, John Podesta, regarding the lame duck session of Congress.
When he arrived, the staff member said, Daschle found Gephardt watching the reaction on a bank of four televisions in his office.
Republicans, who had thought the tide was turning toward Bush, were outraged, accusing the state court of putting politics above the law.
''Four justices of the Florida State Supreme Court have distorted the judicial process into nothing more than a mechanism for providing Mr. Gore with the victory he was unable to win on Nov. 7,'' said House Majority Whip Tom DeLay, a Texas Republican and one of Gore's most vociferous critics.
''This ruling not only contradicts, but assaults, the most basic principles of jurisprudence. ... This judicial aggression must not stand,'' he said.
Oklahoma Representative J.C. Watts, chairman of the House Republican Conference, called the decision, ''a dangerous precedent, which places Vice President Al Gore's recount obsession over the rule of law.''
Senator John F. Kerry said the court decision was necessary to ''protect the integrity of people to have their vote counted.'' But he cautioned, ''depending on the outcome, it could also lead to serious conflict if the Florida Legislature just doesn't like it and certifies its own electors. Then this thing comes to Congress.''
The Bush campaign acted swiftly to try to prevent the recount, including an expected appeal to the US Supreme Court, and a federal filing for an injunction on reexamining the ballots.
Congress weeks ago began to study the question of what would happen if there was controversy in the Electoral College. The issue has been handled largely as an academic possibility.
The Congressional Research Service has produced a memo for lawmakers outlining history and precedent. House Majority Leader Dick Armey, a Texas Republican, has a special section of his Web site devoted to background about the issue.
Some aides said the most important thing Congress has learned from the research so far was that no one has any idea how a challenge would be handled.
The modern process for resolving elections is based on an 1887 law passed after the imbroglio over the Tilden-Hayes race, an election that itself involved disputed recounts.
Congress customarily meets in a joint session on Jan. 6 to receive the Electoral College results, but that date falls on a Saturday next year.
Basically, any one senator and one representative can object, in writing, to electors. If there are objections, the House and Senate vote separately on the issue. The House will be in Republican hands, but the Senate will be split 50-50, opening the potential for conflicting votes and a constitutional mess, aides said.
The law sets out several scenarios in cases of two lists of electors being submitted, according to the Congressional Research Service. But some aides say it is not clear how those scenarios would play out.
''At that point we're in the deep water, there's no clear absolute precedent or guidepath,'' said a top House Democratic aide. He questioned whether a divided Congress would, as expected under the 1887 law, have to accept electors certified by a governor.
