Rupert Cornwell: What am I bid for a Senate seat? Half a million should do it

Out of America: Chicago politics has always been a sewer, but this scandal is a throwback to the days of Al Capone

Whatever his sins, whatever ultimately happens to him, Rod Blagojevich deserves a heartfelt thank-you from his tried and unhappy nation. For a few days at least, there's been something to take minds off the bleak daily news fare of evaporating savings, bankrupt car companies and half a million lost jobs in a single month. Courtesy of the good Governor of Illinois, 300 million Americans have had the laugh of their lives – a scandal that boggles the imagination, but in which no one has lost money and no one has been hurt.

You couldn't make this stuff up. Home-state boy Barack Obama wins the presidency, and even before the result is in, Blagojevich is out to sell, yes sell, his US Senate seat. After all, as he told a crony in a now globally famous chat on 3 November, a day before the election, a seat in the greatest deliberative body on earth "is a fucking valuable thing: you don't just give it away for nothing". And, if further extracts from the federal wiretaps are correct, someone quickly came forward with $500,000 (£335,000) on behalf of an un-named "Candidate 5". If Blagojevich is convicted, he could be sent down for 20 years.

Still, you can't help having a sneaking admiration for the man. Everyone from Obama down has told him to resign. The Speaker of the Illinois House of Representatives said it is "outrageous" that he's still around, while the Illinois Attorney General has asked the courts to remove him. If they don't, he'll be impeached. But as of Friday afternoon, the defiant Governor, who was arrested in a dawn police raid on his Chicago home on Tuesday, was still hanging in there.

Indeed, he is reported to be in an "upbeat and positive" mood, and his lawyers insist he still has "important work to do for the people of Illinois" – such as seeking a more lenient plea bargain arrangement, for instance?

Part of the pleasure lies in hoary caricatures that have again been proved true. We all knew Chicago and Illinois politics was a sewer. Now we have a profanity-spewing Chicago-born governor offering a US Senate seat to the highest bidder; putting the squeeze on the local paper; and enforcing the Chicago political speciality of "pay to play" bribes, or"contributions", in return for a slice of city or state business. And this guy wanted to run for president in 2016?

And just like in the gangster movies, there are good guys as well. Federal District Attorney Patrick Fitzgerald (who prosecuted former governor George Ryan, currently serving a six-year prison term for corruption), could be a reincarnation of Eliot Ness, federal agent and nemesis of Al Capone, with a similar mission of cleaning up Chicago.

Of course, it hasn't been fun for everyone. A few weeks ago, Obama's state and adopted city were brimming with pride about the local boy made good. Now they're squirming. "When people ask me where I'm from, I say Indiana," a neighbour from Illinois told me, only partly in jest.

Nor, of course, has Blagojevich done the president-elect himself any favours. The two were not close; alone among leading elected Illinois officials, the Governor was not given a speaking slot at the Denver nominating convention. Nothing has yet emerged to link the transition team with the bizarre goings-on, and the president-elect is said to be "appalled". But it's turned the spotlight on the grubby habits of the state where Obama's political career began. Once again, disreputable former associates – however distant – such as the convicted graft peddler Tony Rezko, once an Obama fund-raiser, are in the headlines.

Fitzgerald stresses that there is no hint of impropriety by Obama. But hometown sleaze is not what he wanted to be talking about as he set about building a new administration to open a new chapter in Washington. And the whole thing has been a shot of adrenaline for Rush Limbaugh and his fellow conservative talk-show hosts.

By now, moreover, the initial shock is wearing off. The charges against Blagojevich are appalling. Even if no money actually changed hands, he was, as one prominent defence lawyer put it, at the very least "defrauding the citizens of Illinois of their right to his honest services". But how much worse is this affair than business as usual in US politics?

The process is polluted by money. All told, the 2008 election cost $5.3bn, with $2.4bn poured into the presidential campaign alone. The line between the politicians, lobbyists and downright bribery is often blurred.

Last week, some outraged voters with a sense of humour briefly ran a mock auction for a "slightly worn" US Senate seat on eBay. But they could be equally outraged at what some other state governors have done in comparable circumstances.

A few years ago, the former Alaska senator Frank Murkowski had himself elected governor of the state, and then appointed his daughter to his old seat. It now seems that vice president-elect Joe Biden's seat is being kept warm by Delaware's Governor on behalf of his son. Why should governors anywhere be able to bypass the democratic process, even without an auction?

Whatever else happens in Illinois, the rules will be changed so that Obama's replacement will be chosen not by Blagojevich's successor, but by the entire population of the state. In the meantime, Americans can enjoy some good dishonest fun.