Oh so long ago, sometime last spring or summer, months after he'd decisively lost the Democratic presidential nomination, John Edwards admitted that he'd had an affair with some lady who sort of worked for him. Pundits were aghast because OMG, what if he'd gotten the nomination and then admitted to the affair? He could never have been elected president, because American voters simply do not care for politicians who have affairs. (Which is to say, politicians.)
Now we have our first test case for the 2012 election: the brave Nevada Senator John Ensign, who said he'd had an affair with a campaign staffer for eight or so months between 2007 and 2008. Assuming the rumors about his possible presidential candidacy are true, that gives the public a good two and a half years to forget about his great malfeasance before they're asked to actually render judgment in the Republican primaries.
So there are really two questions here: No. 1 are Americans in general ready to have a known (and admitted!) adulterer as a candidate for higher office? And No. 2 are Republicans in particular ready for such a thing?
GOP primary voters in Iowa are no joke when it comes to cultural conservatism, which is why twice- and thrice-married politicians such as John McCain and Rudy Giuliani skipped the Iowa caucuses in 2008. They will probably not like this Ensign fellow so much, even in a couple years. So could the candidate just write off Iowa and continue on to glorious victory in all the other states?
Well, John McCain certainly did! Plus Ensign has a lot of hair, which voters across the country tend to appreciate, and his silver mane will fare well in comparison to (presumptive) primary opponent Mitt Romney's mostly brown coif, which might end up looking too callow and youthful. Additionally, Ensign favors pinstriped suits, which convey equal parts gravitas and gangster: a winning look for anyone vying to be commander-in-chief.
As to his politics or his conservative credentials, SNOOZE. Nobody cares about that. All people will care about in 2012 is that John Ensign once managed to engage in a routine, consensual affair with an adult woman, and for politicians that's about as close as you can get to marital fidelity these days.