This is a thought experiment.
Imagine you are Karl Rove. Your assignment is to attack Bernie Sanders. What do you do?
1. Since his favorability ratings are so high, you need to go after those.
2. Since he has a reputation for “telling it like it is”, you have to attack his credibility as a truth teller.
3. Since he is presenting himself as an agent of the 99%, you have to attack his personal integrity with respect to financial dealings.
Hmmmm.