Former senator william s. cohen noted that "the danger inherent in a congressional committee investigtion is that the person under scrutiny willnot...

There are plenty of examples to choose from to reinforce this idea.  Clarence Thomas now has a lifetime appointment to the Supreme Court, but no one who was alive and watching during his confirmation hearings is going to forget the lurid details of the sexual harassment charges against him in the early 1990's.

During the McCarthy Era of the Second Red Scare, thousands of Americans had their careers and reputations destroyed simply by public association with the idea of communism.  They never received an apology or compensation for this.

Some would argue that Bill Clinton's crime of perjury in the late 1990s, given that he lied about an affair which was not illegal even if it was unpopular and immoral, was not worth a year and a half long investigation and $34 million in costs, but right or wrong, his Presidency will forever be associated with that one event.  True, Clinton already had a bad reputation in that department, but the congressional impeachment hearings were quite the circus, and they had their desired effect.