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.