If Trump asked him to pay off mistresses it is Cohen's responsibility to tell him "No". If he insists tell him to find another attorney.
If you conspire with your lawyer to do something illegal...you BOTH have committed crimes
But what if the client didn't know it was illegal?
Alan Dershowitz:
"if they claim that the president authorized him to do it or directed him to do it, it is not a crime for anybody. If Cohen did it on his own, then it is a crime for Cohen but not the president.
This is going to be a very difficult case for the prosecution to make, precisely because the laws on election are so convoluted."