I think Trump has a solid base of 40%. That is a strong base in a three way race.
Abe Lincoln when he ran, there were four candidates, and ALL FOUR got Electoral College votes. Lincoln won with I believe 34% of the vote. He won largely because the Democrats were divided with two candidates.
It depends on WHO is the 3rd candidate as to who they draw votes away from. If it is Mr. Starbuck, he will draw votes away from the Dems. The moron Amash will not draw votes to any consequential degree. He is an utter idiot.
I say Trump has a lock on this election, unless Clinton runs. If she does, she easily gets the nomination, and depending on how she runs her campaign and how strong the economy is, will dictate what happens. Any other Democrat, and Trump rolls over them like he is paving the road.