It's probably similar to why so many conservatives who have lambasted Clinton for her supposed dishonesty have enthusiastically embraced a pathological liar that easily puts her to shame in the 'dishonesty' category. They never cared about honesty, they cared about finding reasons to dislike their political enemies.
For most people politics is like rooting for a sports team but even less rational. Generally sports fans may have some bias but are self aware enough to realize that while they may prefer their team over others they are not actually the best/most skillful team. Sadly this is not the case for politics for the most part.
But that is the problem with living in a country with these perpetual false equivalencies. Not all acts are equal. I always find it amazing that Republicans have been lambasting Hilary for Benghazi, an act she tangentially had anything to do with when Bush literally lied the country to take us to war. A war that killed thousand more Americans and 100,000 more people than Benghazi. Where was all this outrage then?
Btw, I was stunned watching Chris Christie last night attempt to "prosecute" Hilary. The fact that the Trump campaign allowed him on stage to even mention the word prosecution amid all that is happening in Jersey, should tell everyone how much Trump believes in Law and Order, the elites vs. the rest of us and rigged systems.