Sex scandals are no bar to public office...

Out of America ... as Bill Clinton showed. The US is now the land of second chances for politicians caught with prostitutes or mistresses

If America is the land of opportunity, it is also the land of second chances. Consider the case of Anthony Weiner, forced to resign from Congress for sending pictures of his nether regions to various female followers on Twitter. Now, just a couple of years later, he's running for Mayor of New York – one of the highest-profile political jobs in the country – and, if polls are to be believed, with a fair chance of winning.

Or what about Eliot Spitzer, whose record as a tough-talking prosecutor who vowed to stamp out corruption and clean up Wall Street once won him the governorship of New York state? Alas, the man who went after prostitution rackets was found to be a client of a high-end prostitution business. However this disgrace didn't prevent Spitzer from getting his own talk-shows on cable TV. And now he's back in the political game, running for Comptroller of New York City, in charge of the city's finances. Not the most exciting post on earth, perhaps, but just the sort to launch a new career. And as with Weiner, the polls show him in the lead, ahead of September's Democratic primary – which in an overwhelmingly Democrat city might as well be the election itself.

The mind boggles at the prospect of a Weiner/Spitzer administration: whatever happened to the old-fashioned sex scandal? Of course, these might be two instances of peculiarly New York chutzpah, proof of how no city breeds thicker political skins. Except that such comebacks are happening everywhere, even in the South, which you would imagine to be more conservative and strait-laced about such matters.

In 2009, the Republican Mark Sanford stepped down as governor of South Carolina, when it emerged that far from "hiking the Appalachian Trail" (as one sudden disappearance was explained by his press man) he was actually in Buenos Aires seeing his Argentine mistress. That, one might have thought, was that. But exactly four years later – divorced from his former wife and engaged to his old flame – Sanford has just been elected to Congress.

Or take David Vitter, the Republican Senator from Louisiana, advocate of sexual abstinence for teenagers and arch-foe of gay marriage, who in 2007 was found to be a client of a Washington-based prostitution service. But in 2010, Louisiana's voters re-elected him by a 19-point margin, and his dealings with Deborah Palfrey, the so-called "DC Madam", who subsequently committed suicide rather than face a lengthy jail term, are apparently forgotten.

Now, you could advance a specific explanation for each of these comebacks. Weiner and Spitzer are running in pretty low-calibre fields, in which name recognition is all – and both have plenty of that. As for Sanford, having squeaked through the primary, he was a certainty in the general election for a seat that Caligula's horse would have won, as long as it was decked in GOP red. And had Vitter been forced to resign when the scandal broke, Louisiana's Democratic governor would have appointed a Democrat to succeed him. Republicans had little choice but to rally round.

And more broadly, politicians are a breed apart. What sane individual, once disgraced, would want to get back into a profession where the pay isn't great, where you have to fund-raise virtually round the clock to finance campaigns that begin the moment the previous one is over and where, in Washington, you join an all-but-dysfunctional Congress? No wonder the best-qualified people in the US shun politics. To put yourself through the grinder a second time, in the sure knowledge that your previous indiscretions will be brought up ad nauseam, is even more remarkable. You must have a gigantic ego, bottomless self-belief and an unquenchable lust for vindication. Spitzer and Weiner, by common consent, are liberally endowed with all three qualities.

Nonetheless something has changed: yes, some sex scandals are fatal, but these invariably involve more than mere straying from the marital bed. The former Democratic presidential candidate John Edwards always seemed slippery, glib and untrustworthy. Revelation of his extra-marital affair, when he betrayed his cancer-stricken wife and went to extraordinary lengths to cover it up, cemented that impression, ending his career and turning him into a political pariah. So too the demise of Nevada's Republican Senator John Ensign. It was not Ensign's affair with a close aide's wife that finished him, but ethics violations linked to the cover-up.

But these days, such instances are a minority. Americans seem to be growing more tolerant of the sexual peccadilloes of their elected representatives. You might not think so, perusing the lurid tabloid headlines greeting Messrs Weiner's and Spitzer's return to the fray – but in 2007, a Gallup poll found almost half of Americans "would not mind" if a presidential candidate had an affair.

That's not exactly a French level of nonchalance, and Gallup's findings came two decades too late to save Gary Hart, chased – amid national ridicule – from the 1988 presidential race after revelation of his liaison with Donna Rice on board a yacht called Monkey Business. All the same, it's a small revolution in American moeurs, for which Bill Clinton, above all, surely deserves the credit.

The 42nd president rewrote the rules of sex scandals. Gennifer Flowers and sundry other "bimbo eruptions" didn't stop him getting elected in 1992, and despite the Monica Lewinsky scandal (in which, admittedly, his Republican enemies crassly overplayed their hand) he left office in 2001 more popular than ever.

Not everyone, of course, is as lovable, and thus as forgivable, as Bill Clinton. But since his time, social media and reality TV have further changed the rules. All privacy is relative, but on the other hand, today's insatiable 24/7 news cycle compresses a scandal's life, while attention spans are shorter than ever. As a result, almost nothing shocks. Asked if there was any way he could lose an election, Louisiana's rogue of a former governor, Edwin Edwards, once replied: "Only if I'm found in bed with a live boy or a dead girl." These days he might even get away with that.