I will try to keep this simple. There is one overriding issue in this election. It is of course immigration. If we don't get a handle on it, the other issues really don't matter because we are going to end up being Mexifornia in a couple of election cycles anyway.
Trump is the only candidate with a shred of credibility on immigration. He has staked his reputation on building a wall and all that goes with it. I like Cruz, but he is full of dissembling on immigration. He is not building a wall. He's obviously a lot better than Rubio, who answers to the Chamber of Commerce and donor class, but he isn't Trump.
The other issue that is crucial is foreign affairs. For some reason the establishment republican position is we need to restart the Cold War and engage in endless interventions in the middle east. Trump is the only remaining republican candidate who is openly skeptical about any of that. The rest of them act like the Iraq war as a big success that we should emulate, and that the only problem was the Obama wasn't willing to keep US troops there for generations.
I would obviously prefer that Trump was more conservative but he is not a deep political thinker. What exactly has all our loyal support of the brand name conservatives gotten us? Planned Parenthood still receives hundreds of millions of dollars of tax money, and the guy who exposed them is facing felony indictments. Obama's illegal executive orders continue in place. Our borders are wide open to an invasion. The IRS scandal is no closer to being resolved. Gay marriage has been shoved down our throats, much as abortion was. Obamacare was fully funded. We elected republican majorities to both houses of congress, most whom ran on platforms of stopping all of this. What did we get? Bumpus, that's what. They folded at the first sign of opposition from Obama. Worse, they set up this insulting charade where they pretended to vote against things that they had already stacked the deck to ensure passage, like the Iran nuke deal or this new trade deal.
The republican grandees and a good portion of the so-called conservative commentariat make no secret of the fact that they are personally embarrassed to be associated with people like the republican base. They want us to be like the blacks are for the democrats: do what we are told and shut up. Well, it's not going down like that. They can't win without us, but we can get along fine without them.