Although a hypothetical question, this is one many of us have on our minds. I agree with @Nicholas83, many of these people already have violent tendencies, and this is why some “liberals” I know in my inner circle have decided to purchase a gun (for defensive purposes to be clear, not offensive). There is plenty of evidence that Trump has no issue blowing dog whistles, therefore I am guessing that if/when Trump goes down he will clap his tiny hands in excitement when he watches his supporters become violent in his defense.
I am tired of watching the United States lower its standards for the Trumpsters, therefore I am piggy backing on the callers question by asking this hypothetical: Considering the Republicans, their agenda, what they have already accomplished, and indications that they may have no intentions of fixing the problem they created (Trump), how bad would it have to get before there is an uprising? What does history suggest when looking at other countries that have faced a potential constitutional crisis?