Rich Lowry pretty much nails it (emphasis mine):
Bill Clinton told 60 Minutes in his promotional appearance for his book, My Life, that he wears his impeachment as a "badge of honor." As far as honors go, it's a far cry from the Distinguished Service Cross or the Presidential Medal of Freedom. But Clinton has to pretend to cherish it. It is imperative for his legacy that he portray his impeachment as illegitimate, as the work of hateful fanatics.
The truth is that the scandals and investigations that built toward Clinton's impeachment -- from Whitewater to the China fundraising scandal to Monica Lewinsky -- were a product of the world created by post-Watergate liberals. They created the independent-counsel statute; they celebrated an adversarial press; they wrote exacting campaign-finance rules; they instituted an anti-sexual-harassment regime in the workplace -- and then they supported an attempt to defy all of it when it inconvenienced Bill Clinton.