The Democrats could be celebrating an historic win in Congress as well as the White House

With the election just a week away, the American presidential campaign is getting louder, nastier, more dramatic. And loudest, nastiest and most dramatic of all are those on the Right who are putting their last and best efforts into proving that Barack Obama is a radical, a secret Muslim, even a communist.

A few weeks ago, one talk show host put together a television programme entitled Obama and Friends: History of Radicalism. Last Thursday, a Florida interviewer, picking up the theme, asked Joe Biden, Obama’s vice-presidential candidate, if Obama was a "Marxist", and wondered what he thought about "the people who say Barack Obama wants to turn America into a socialist country much like Sweden".

Maybe some of this sort of thing will stick; maybe it will cost Obama some votes. Maybe, even, it will cost him the election (and stunning upsets do happen). But in the meantime, this sort of argument is having another effect as well: it is helping to destroy Republican Congressional and Senatorial campaigns, one by one.

Voters might be spooked by Obama, who really is the least experienced, least tested, presidential candidate in modern history. But anxiety about Obama seems to make voters even more determined to punish the Republican party for its nastiness and partisanship - and, of course, for the financial crisis, the Iraq war, and eight years of George W. Bush. All of which could mean that America’s far more experienced, tested and dedicated Left - the Congressional and Senate Democrats - are about to win a victory of historic proportions.

According to a poll in USA Today, some nine, currently Republican seats in the House of Representatives (the lower house) are likely to vote or leaning Democratic; another 24 are too close to call. By contrast, there is only one Congressional race where a Republican is likely to take a Democrat’s seat, despite the fact that the current Congress, which already has a Democratic majority, is none too popular. David Frum, one of the American Right’s most prominent pundits, has publicly called on the Republican party to throw its last remaining dollars not at the presidential race, but at the Congressional campaigns.

"There is not a safe Republican seat in the country," he writes in Sunday’s Washington Post, quoting a Republican congressman who explained further: "I don’t mean that we’re going to lose all of them. But we could lose any of them."

Meanwhile something nearing 10 seats in the Senate (upper house) - including one in Sarah Palin’s home state, Alaska - could switch from Republican to Democrat, too. Not only are Republican Senators in trouble in liberal New England, but they’re also facing unexpected challenges in formerly safe Republican states in the once-conservative south. In North Carolina, Senator Elizabeth Dole, wife of former Republican presidential candidate Bob Dole, is in trouble; so is Senator Saxby Chambliss of Georgia. Who knew there were even any Democrats in Georgia at all?

Improbably, a Democrat is also a serious contender for the Senate race in Minnesota, despite the fact that the candidate, Al Franken, is better known as a comedian, and not one of your kinder, gentler comedians either. Franken is a veteran of Saturday Night Live - now best known for its vicious parodies of Sarah Palin - and, among other things, the author of an infamous article on virtual sex, published in Playboy, about which not everybody got the joke.

Yet so close is the Minnesota race that Hillary Clinton has flown in to support Franken, while Rudy Giuliani, a former New York mayor, has been on the stump for his opponent, Norm Coleman. Together, the two campaigns have spent more than $32 million on the race, one of the most expensive in the country. But there’s a reason for this extra effort, of course, beyond the mere desire to win: in America, a political party that has more than 60 Senators and a large House majority is far more powerful than one with an ordinary majority, of the kind the Democrats enjoy at the moment.

Not only would higher numbers give the Democrats the ability to pass legislation without fear of a Republican filibuster in the Senate, a two-thirds majority in both the House and the Senate would give the Democrats the ability to override a presidential veto if they so wished. Indeed, a technical two-thirds majority isn’t even necessary, as long as there are enough centrist Republicans to throw in to the mix.

In which case, it won’t make any difference if Obama turns out to be a Marxist, a communist, or a secretive Right-wing capitalist: in the US system, Congress writes and passes legislation, not the president. If American politics look very different a couple of months from now, it won’t only be because the occupant of the White House has changed.