Harman is said to have linked her efforts to help 2 lobbyists who were being investigated to efforts by donors to help her get named Chairwoman of a power Congressional Committee.
This seems to be hardball politics. I wouldn't press any charges.
My standard is whether Harman was doing something either against U.S. interests (no) or something she otherwise wouldn't do in exchange for something personally valuable to her. (no)
Furthermore, all of these "pay to play" scandals that involve campaign funds are bogus to me because unless there is something untoward done with the campaign funds (and that would be the crime), the money is going to be used for a public purpose.
The problems occur when there is personal gain involved like what is alleged with Former Alaska Senator Ted Stevens. He is said to have had work done on his house. Or Rep. William Jefferson who had cash.
We need to separate the public from the private.
Also, we need to make sure we don't allow those who are trying to undermine our system pursue little cases and morph them into major scandals.