Trump is dangerous because either he doesn't think about what he says or he considers, carefully, what he says.  E.G.  If one claims that an election is rigged, then one can claim that the results are not legitimate.  If one claims the results of the ballot are illegitimate then one can propose that the government is not lawful and that it can be resisted non-violently or violently.  The boundary between 'free speech' and 'action' is quite clear when people organize and take to the streets in protest, to the ballot box, or take up arms in rebellion.  Trump's remarks, at no cost to himself,  even if a hinted suggestion, have the ability to sanctify the latter (organized rebellion against an illegimate government).  Trump can argue that he didn't say this, but the logic implies it.  So does he say these things without thinking or does he think about what he says?