To me, "Alpha male" denotes a man who has intrinsic leadership characteristics, regardless of the direction that leadership might lead. He is the one who, in a group of men, naturally dominates the conversation, and in any decisions that need to be taken by the group, he is usually the one whose viewpoint carries the day. The late Mr. Hitler of Germany was the most obvious Alpha Male of the past hundred years. He took the people of Germany wherever the **** he wanted to take them.
Trump is an "Alpha male," whether you like him or not. He has taken a whole political party and shifted its focus (foci) in the directions he chose, even as they might conflict with previous Republican thinking.
Contrast this with President Clinton, whose "triangulation" strategy was basically to find the current trend, then rush to the head of it, pretending to lead. He did this with welfare "reform," as you might recall.