Should Vitter Quit?

I don't think so. He's human. But Vitter himself has written otherwise:

Some current polls may suggest that people are turned off by the whole Clinton mess and don't care -- because the stock market is good, the Clinton spin machine is even better or other reasons. But that doesn't answer the question of whether President Clinton should be impeached and removed from office because he is morally unfit to govern.

The writings of the Founding Fathers are very instructive on this issue. They are not cast in terms of political effectiveness at all but in terms of right and wrong -- moral fitness. Hamilton writes in the Federalists Papers:

(No. 65) that impeachable offenses are those that "proceed from the misconduct of public men, or, in other words, from the abuse or violation of some public trust."