Money that comes from the public is a vote of confidence.
But Clinton was impeached by a political process where money was not the main issue.
The public as a whole seems to have been on Clinton's side, but the will of the public was not represented by the legal system.
Point being, Clinton makes more money giving speeches than he ever did sitting in the White House collecting a salary :p
I think the beauty of money being exchanged in a free market is that it really shows you what society cares about. But the Presidency is not decided by money, so it's a totally different system and the money theory is not applicable.