There are many reasons people are voting for Trump, but I'll state the few that come to mind (for the record, if I vote for Trump it is solely based on point 1, because I'm sick of babies getting slaughtered without a say in the matter, and I don't really fully agree or agree at all with the other points):
1) He will appoint conservatives to the Supreme Court. He has pledged to do it multiple times, even showing a list of his top options. If he weren't to follow through on this it would be political suicide. Even if he himself isn't conservative (truly), as long as he surrounds himself with conservatives it is slightly appealing.
2) Despite this new politically correct world we live in, there are a huge amount of people that just can't take the muslims anymore. They have been jihading to their own deaths and to the deaths of others for over a thousand years now and at some point, people aren't going to buy into the notion that islam is a religion of peace. I see people say that only 5-10% of muslims are violent. Ok, and there are what, a billion muslims, so that means that 50,000,000 - 100,000,000 muslims are violate, that is a huge freaking number! Not to mention you rarely see the "non" violent muslims physically try to stop the violent ones. Sure, they say what they do is bad (sometimes), but a lot of them passively are supportive of their actions even if they don't want to do the stuff themselves.
3) The immigration problem is very harmful to our southern states. I live in Missouri, I don't have to deal with the problems, economically and job wise, that Texas has to with illegal immigrants. Most the U.S. doesn't have to deal with those issues, and yet many U.S. people seem to think they know what's best for the states that actually border a country that encourages its people to go over the border illegally to get money, then send it back home.
4) People are just sick of politicians. For this group of people, it lierally doesn't get more complex than this, they are just done with political dynasties.
5) The Bernie supporters that just hate how corrupt Clinton was with the DNC nomination.
6) The Americans who would rather vote for a bafoon than someone who, countless times, gets away with breaking all sorts of laws.
I believe I've said enough, though I'm sure there are a bunch more reasons.