At the start of a week that will see Republicans and Democrats back in the debating studio, a battery of issues - from Bill Bradley's undeclared heart problem to George W Bush's suspect brainpower, from the fate of a boy from Cuba to the right of homosexuals to serve in the US military - has injected a set of imponderables into the political equation.
Most is at stake for Mr Bush, whose performance in the two most recent debates has been rated even by supporters as "disappointing". Mr Bush's discomfort under even relatively mild questioning and his lack of spontaneity have allowed murmured doubts about his intellect to become dangerously open ridicule.
Mr Bush's academic record is not of the best; he averaged C grades at Yale. But his team insists that leadership is not in the small print of specifics, but in overall vision and command. Yet when a New Hampshire newspaper endorsed one of his rivals, Steve Forbes, and described Mr Bush as an "empty suit", that too hit home.
An equally serious, but quite different, uncertainty has entered the Democratic race, after Vice-President Al Gore's single challenger, Bill Bradley, cut short his campaigning on the west coast and owned up to a hitherto unsuspected irregular heartbeat. He and his team swiftly produced medical reports and a succession of cardiologists to stress that 2 million Americans had the same problem and led normal lives. And Mr Bradley was back campaigning in Florida yesterday, laughing off the scare as the result of forgetting to take his pills.
But the weekend illustrated how quickly not just the fortunes of candidates can change, but the political context of the campaign also. Two issues, the fate of the six-year-old Cuban boy rescued off Miami on Thanksgiving Day, and the conviction of a serviceman for murdering a gay colleague as he slept, are testing the political acumen and sensitivity of the candidates.
The "gays in the military" issue was reopened by Hillary Clinton who said bluntly that the "don't ask, don't tell" policy set by her husband had not worked. Mr Gore, who is courting votes in the conservative south, has not yet pronounced on the question. Mr Bradley has said from the start that he supports the right of homosexuals to serve in the military. Mr Bush, also with an eye to the southern vote, has refused to meet leaders of the main gay Republican group.
The dispute over the Cuban boy, however, is a political minefield where the votes of the Cuban exile community in Florida, if not the Hispanic vote elsewhere are at risk. Mr McCain pioneered what has become the standard candidates' line: give the boy's father a visa to come to Florida. The assumption is that the father will see the wonders of life in America and decide either to stay, or let his son stay, thereby depriving the Cuban leader, Fidel Castro, of a propaganda coup if the boy was returned.Reuse content