He can't drop out.
He is not a winner, far from, but sees himself as one. Dropping out would be admitting he has been lying to himself.
Plus of course dropping out would have repercussions on his pending legal cases.
Si far no, he and many others haven't, while requiring the muslim community to condemn the killings.
They'll just continue their narrative that the police and politicians are to blame.
Trump withdrawing from the debate would not annoy the democrats but embolden them. It just adds to their campaign that Trump is afraid to talk about the issues.