How come Americans voted for Trump?

Well...it's a two party system here so it was either him or Hillary. There was a wave of momentum from people wanting "change" from the perception of what many viewed as a stagnant/corrupt government. Trump was an outsider that many expected to flip things upside down....and in many ways he has. It's the same story no matter who is President in this country....you have the loyalists that will defend him no matter what, you have those against that will hate no matter what, and then you have the mass of people in the middle that live their lives and just wait until the next time they have to pick a favorite from a group of assholes.