Is that not because Trump was a political newcomer?
He had no record to bring to light. He had never failed to pass a bill, voted on the wrong side of history, or been caught in controversial special interests dealings.
Because he had never held office.
Therefore, one can only look at the person, and in Trump’s case, his business endeavors (especially the massive failures) in order to make a case against his election.
So, in short, I reject your premise that Clinton ran a dirty campaign… The fact is that you’ve cherry-picked data that would have been different had Clinton’s opponent been Rubio or Cruz or Bush. Only because it was Trump was it personal, again, because of his nonexistent record.
Oh, and remember how conservatives tried to use Jeremiah Wright and “community organizing” to try to sink Obama?
Turnabout is fair play.