Simply put, it is a strategic error to sanctify the idea that it’s worse when Republicans cheat. The hypocrisy charge exacts a double penalty on Republicans where none exists for Democrats — first, in the accusation of hypocrisy itself, and second, in the media whipping social conservatives into a frenzy in a bid to belatedly “enforce” their moral code — exactly the thing the secular media believes you shouldn’t do 364 days out of the year — to hound a Republican out of office.
Some will argue that conservatives should enforce a higher standard upon themselves. In cases of corruption or illegality, I have agreed. The stench of systemic corruption can be grist for severe electoral losses, as it was in 2006, and from a party-strategic perspective must be purged immediately. But adultery is different — a human failing that strikes Democrats and Republicans equally, and one in which there is a certain presumption of privacy unless there is illegal behavior (Clinton, Spitzer) or it affects job performance (Sanford). Do Republicans want to purge their ranks based exclusively on a test of personal moral conduct? How exactly does this help solve the (inaccurate, IMO) perception of the Republican Party as intolerant and dominated by the religious right?