Trump has no real base of power within the Republican party. Those Republicans who accept appointments to his administration are not going to commit political suicide by joining him in something insane. The fbi, military, etc will not follow illegal unconstitutional orders. Trump will be left to rant and yell all alone. He won't be heading a corporation where he effectively has absolute control, he can not get his way as he is used to. Politics in the US doesn't work that way. The US government is designed to prevent such things. Yes the Republican Congress would probably love to impeach him and get one of their own, Pence, into the office. White House security will escort Trump to the door if need be. A coup, a civil war, by who? Most of his voters don't like him, they just hate Hillary more. Some Bernie voters at the Dem Convention are being interviewed and saying they'd rather have Trump and four years of gridlock. This election is truly about two disliked candidates and people voting for the one they dislike the least. Whoever wins there will be no mandate and likely gridlock.