Nowhere, apparently, because, as Vitter says, "Anybody who looks at the two cases [his and Eliot Spitzer's] will see there is an enormous difference between the two of them. The people that are trying to draw comparisons to the two cases are people who've never agreed with me on important issues like immigration and other things."
Well, now we all understand. That explains why Sen. Vitter is still in the US Senate and why his fellow family-values Republican senators seem OK with that. There are prostitution scandals and prostitution scandals, and, according to Vitter and the Republicans in the Senate, Vitter's prostitution scandal doesn't meet the resignation test.
Sen. Vitter's quote taken from the Times-Picayune.