For more than two weeks, Florida's ballot saga has spun out more plot twists than a Tom Clancy thriller. But Day 15 surpassed them all.

George W. Bush ended it on an upswing, though not before his prospects - and quite possibly his spirits - hit their lowest point since election night.

The turnaround came when Florida Democratic officials stunned Al Gore's campaign by aborting a manual recount in vote-rich Miami-Dade County. That decision is potentially a fatal blow to Gore's chances of overtaking Bush, as hand counters in two other counties race to meet a Sunday deadline.

The Texas governor's slender edge in Florida has been chopped down to 801 votes, out of nearly 6 million cast, according to the latest unofficial total. And it is by no means clear that the piles of ballots still to be counted will contain enough additional Gore votes to change the outcome.

When the history of the presidential election is written, Nov. 22 may well be viewed as a turning point. Among the major events of a fast-moving day:

Republican vice presidential candidate Dick Cheney suffered a mild heart attack, and doctors inserted a stent to open a 90 percent-clogged artery. The 59-year-old Bush transition chief, who has a history of heart problems, was admitted to a Washington hospital in the predawn hours after experiencing chest pains at his northern Virginia home.

The U.S. Supreme Court - where some politicians believe the election will ultimately be decided - was drawn into the fray for the first time. The Bush camp asked the court to reverse the Florida Supreme Court's landmark order, which requires hand recounts - that currently favor Gore - included in the official vote tally. A ruling by the justices could come as early as tomorrow.

Gore's campaign rushed back into court to try to force Miami-Dade County to resume its hand recount. The county's Democratic controlled canvassing board said it wasn't sure it could meet a Sunday deadline set by the state Supreme Court for completing its count. The board also voted not to submit the results of its partial recount, which had already netted Gore 157 votes. A state appeals court last night upheld the decision to stop the count, and the Gore campaign vowed to appeal to the Florida Supreme Court.

What seemed to be another court victory for Gore was in danger of melting away. A Palm Beach judge, in an order late in the afternoon, appeared to sanction the counting of "dimpled ballots," those in which the vote failed to penetrate the computer card. But the county canvassing board indicated that it might stick to a tougher standard. Lawyers for Bush and Gore were invited to thrash out that issue tomorrow morning, before counting resumes.

Republicans in the GOP-dominated Florida legislature threatened to call a special session to reverse the state Supreme Court's order and award the state's 25 electoral votes to Bush. The Republican speaker of the Florida House accused the court of sparking "a potential constitutional crisis" in the state.

The state Supreme Court's ruling had initially been regarded as a major victory for Gore. It appeared to open the way for him to pick up enough votes to snatch Florida's 25 electoral votes away from Bush-and with it the presidency.

A smiling Gore, with his running mate, Sen. Joseph I. Lieberman at his side, had welcomed the ruling with a short TV speech from the vice-president's residence late Tuesday night. Bush, meantime, kept out of public sight behind the iron gates of the Texas governor's mansion in Austin.

It was left to former Secretary of State James A. Baker III to launch the Bush camp's counter-attack, in a blistering attack that ran past midnight and into yesterday morning. Baker accused Florida's highest court of rewriting the state's election law and left no doubt that the Bush forces were prepared to do whatever it took to prevent the ruling from deciding the election.

Less than six hours after Baker spoke, Bush was awakened in Austin by a call from his close friend and campaign chairman, Don Evans. The news: Dick Cheney had suffered chest pains and had been hospitalized in the nation's capital at 4:30 a.m.

A few hours later, it was Bush's turn to address the nation from a presidential setting. Dressed in a business suit, a U.S. flag behind him, the governor began his remarks from the Texas Capitol with an upbeat report on his running mate's condition.

"He had no heart attack. I'm pleased to report that," said Bush. "Dick Cheney is healthy."

Aides said later that Bush was unware that, at that moment, Cheney lay on his back in the cardiac unit at George Washington hospital, a few blocks from the White House. Doctors were threading a catheter into a coronary artery and inserting a stainless steel stent to improve the flow of blood to his heart. Tests would confirm that he had suffered a mild heart attack, at least his fourth since 1978.

In Bush's TV speech, he picked up where Baker had left off in his assault on the Florida court's unanimous ruling. The Republican nominee accused the justices of legislating from the bench in an attempt to "usurp" the authority of Florida election officials, including the secretary of state, Republican Katherine Harris.

"Make no mistake. The court rewrote the law. It changed the rules, and it did so after the election was over," Bush said in a firm, clear voice.

Bush went on to declare his belief that he had won the election. He also appeared, for the first time, to question the legitimacy of a Gore presidency, should the Democrat wind up winning the election.

"I believe Secretary Cheney and I won the vote in Florida," he said. "I believe some are determined to keep counting in an effort to change the legitimate result."

Bush did not respond to Gore's request, renewed the night before, for a face-to-face meeting between the two candidates. But the governor made an offer of his own: that Gore call on local election officials in Florida to count all military ballots that were signed an received on time.

Later in the day, the Bush campaign filed a lawsuit in Tallahassee, asking 13 counties to reconsider hundreds of disqualified military ballots. News reports from Florida indicate that the proportion of military absentee ballots thrown out last week was no greater than four years ago.

If the courts order more military ballots counted, Bush is likely to gain votes. There were 646 overseas ballots disqualified in the affected counties; it is not known how many were from members of the armed forces.

While Bush was making his first statements on the Florida Supreme Court decision, it was Gore's day to avoid public comments. The vice president and his wife packed boxes of food for the needy, as they do each Thanksgiving season, while campaign chairman Willliam Daley prepared to speak to reporters outside the vice-president's residence, Gore's command post for much of the past two weeks.

Just before Daley stepped out to give an optimistic report on developments in Florida, the Miami-Dade canvassing board cut the Gore camp off at the knees.

On a unanimous vote, following a morning of acrimony that included raucous Republicans protesting the recount , Miami Dade's Democratic canvassing board opted to abandon its manual recount.

David Leahy, the board chairman, explained that it seemed impossible to recount more than 617,000 ballots by the 5 p.m. Sunday deadline set in the Florida Supreme Court's ruling Tuesday. (actually, the justices had left Harris, the secretary of state, the option of giving the counties until 9 a.m. on Monday; she declined).

A partial count might disenfranchise some voters in the county, Leahy said, in explaining the board's decision to return to its Nov. 8th count.

Gore's campaign asked a Florida judge late yesterday for an emergency order to continue the recount and to include the ballots already counted in the final tally. If that request is rejected, Gore would lose 157 votes already tallied-and the possibility of gaining hundreds more.

Clearly shaken, Daley told reporters that the Gore camp was "disappointed" with the Miami-Dade board's decision (the same word Bush had used earlier in the day to describe his reaction to the Supreme Court's ruling).

The two remaining counties, both heavily Democratic, where counts are continuing, have given Gore a net gain of 129 votes so far.

Broward County, where Gore gained 137 votes, has yet to count thousands of disputed ballots. The same is true in Palm Beach County, where Bush has picked up 14 votes. More than half the precincts there remain to be counted.

Democrats maintain that there are still enough potential votes in Broward and Palm Beach to swing the election for Gore. But the vice president's chances would be far brighter, they concede, if Miami-Dade continued to count.

Daley, the Gore chairman, dismissed as "hypothetical" a question about whether the vice president could get enough votes without Miami-Dade to pass Bush by the Sunday deadline.

Not long after he spoke, doctors at George Washington hospital briefed the press and the nation on Cheney's condition. They reported that the GOP vice-presidential nominee would likely be released in two to three days and could resume his normal activities in a few weeks.

Not until a second briefing, however, and a flury of questions from reporters who did not attend the first session, did the doctors concede that Cheney had suffered a "very slight" heart attack.

Cheney's latest heart problems could further complicate the already difficult task facing Bush, as he attempts to make plans to staff a possible new administration while the ballot battle continues. Cheney had been named to head up the Bush transition effort, drawing on his experience as White House chief of staff in the Ford administration.

As doctors in Washington were scrambling to patch their embarassing credibility gap, the Bush campaign was in the process of taking the election to the U.S. Supreme Court.

Arguing that Florida's justices had acted unconstitutionally in requiring that hand recounts be added to the official vote tally, Bush asked the Supreme Court to declare the election at an end and allow Harris to certify a winner on the basis of returns received by last weekend. That, of course, would make Bush the winner.

Unless the justices intervene, Bush lawyers argued, "the consequences may well include the ascension of a president of questionable legitimacy or a constitutional crisis." The current situation in Florida, they added, "borders on anarchy." A ruling could come as early as tomorrow.

Down in Florida, as the day was drawing to a close, Republicans were flexing their political clout and turning up the heat on the Gore campaign.

Republican Rep. Thomas C. Feeney III, the speaker of the state House of Representatives, said he had requested legal advice on the GOP-dominated legislature's role in choosing Florida's electors, should that become necessary.

Feeney echoed the Bush campaign's warning that a crisis is looming and said the state legislature "intends to uphold the Florida constitution." His remarks reflected the Republicans' determination to make sure that the state's 25 electoral votes are counted - for Bush.

"This is Thanksgiving eve," added the GOP leader. "I think we can all relax and take a deep breath, at least for 24 hours."

Gore and Bush planned to spend the holiday in Washington, D.C. and Texas, respectively.

Any hopes for a grander celebration by either man, however, were lost days ago in the uncertainty over the election.

During the campaign, Bush liked to joke that it would be "kind of tough around the old Thanksgiving dinner table" for his younger brother, Jeb, the Florida governor, if he lost the Sunshine State.

A spokeswoman for the Bush campaign said Jeb Bush and his family would be spending the holiday in Florida and will not be with his brother today.