Last week a friend from university grumbled at length about the scandal surrounding former Congressman Mark Foley - the Florida Republican whose unseemly interest in teenage boys is now common knowledge. The Foley scandal, he complained, was drawing focus from the real issues of this campaign: the Iraq war and the Bush administration's general awfulness and incompetence.

This brought to mind a conversation that took place five months ago with another friend from university. He, his wife and I were having breakfast when I remarked that the morning's paper reported that the US government was hesitating to send some of the Guantanamo detainees home for fear that they might be tortured in their home countries. I assumed my friends would join me in relishing the cruel irony of this policy but without even looking up my old roommate said, "Those people deserve whatever they get."

"Absolutely," his wife muttered. I took the hint and, after an awkward pause, changed the subject.

My ex-roommate and his wife are not the couple you might imagine them to be: working class evangelicals from the south or Midwest. They are upscale professionals from New Jersey. Their opinion of Guantanamo is a useful reminder that not all of the president's support on the terrorism issue comes from people we think of as typical Republican voters.

Both vignettes illustrate a truism of politics: that you cannot really predict how people are going to react to any given development in the final days of a campaign.

Conventional wisdom holds that my friend ought to be celebrating. Yet he is convinced the Foley scandal will be bad for the Democrats because it draws focus away from what ought to be their strongest issues.

On one level this is a hard argument to make. For the Republicans, who tout themselves as the guardians of family values and traditional morality, it is difficult to imagine a worse story at a worse moment than the Foley mess. Politicians are most vulnerable when they are seen to be hypocrites. Heading up the House Caucus on Missing & Exploited Children while you go around propositioning teenage boys is hypocrisy on a truly world-class scale.

Yet my friend is convinced that, in the larger scheme, the Foley mess won't be good for the Democrats and elections are strange enough beasts that come November 8 he may well be right.

The thing to remember as one watches these final weeks of campaigning is that mid-term elections are completely different from presidential ones. This is not a national vote but rather a series of local ones. Bush's unpopularity is certainly an issue. But he is not on the ballot anywhere and we don't vote for parties in this country. That makes people's opinion of their individual congressman or senator almost as important as their opinion of the president and his party. Some early indications - a poll last week, research released by the New York Times on Monday - are that the Foley scandal, appalling as it is, may have little effect on individual Congressional races. This also makes it harder to gauge the impact of the other late-season campaign bombshell: Bob Woodward's new book, State of Denial.

The book includes the explosive charge that US Secretary of State Condoleezza Rice ignored a fairly direct warning from the CIA about 9/11. Its author has been omnipresent in the media for the last week or so. And yet, Woodward's portrait of a distracted, clueless president, manipulated by, and overly loyal to, his Machiavellian defence secretary may have less impact than one might imagine.

Woodward's work is most likely to reinforce views of Bush on both sides of the political spectrum. People who have never liked the president will feel vindicated. His supporters will see yet another attack led by the "liberal media elite". Few opinions will actually change.

But - and here's the rub - in a close election one does not actually have to change very many people's opinion. In 1980 pretty much all of the close races broke one way. In state after state relatively small numbers of voters chose the Republican over the Democrat, handing the GOP 12 seats and its first senate majority in a quarter-century.

Six years later it happened again. Conventional wisdom held that the Democrats had no chance of retaking the senate, but in state after state the close votes went their way and the final tally gave them a 10 seat majority. In both cases the result was completely unexpected.

Since it is October and some of us here in the US are paying as much attention to the baseball playoffs as we are to politics, the final word, perhaps, should belong to Yogi Berra. As the great player famously remarked: "It ain't over till it's over."

Gordon Robison is a journalist and consultant based in Burlington, Vermont. He has lived in and reported on the Middle East for two decades, including assignments in Baghdad for both CNN and Fox News.