You know, what Cruz said is spot on. I have talked to a number of Trump supporters and they have absolutely no reason why they are from Trump, except that he’s “gonna build the wall.” They don’t know a thing about the man, how trashy and crude he is. How he has so easily changed his views over a period of a few years and how he gives signs that he just might again. They don’t know about the man who talked about the married women he has had sex with, how he see belittles women (”she would good on her knees”). They don’t know the vindictive Trump who gets even with those who have the audacity to disagree with him. They know very little about the man, save that they are angry and funnel all that anger in him. Yes, I would say that Cruz described many of them to a tee.
Ya know, there once was a guy who changed his views on a dime and many of his fellow citizens funneled all their anger through......
Republicans - at least some of them -- have promised border security but have not come through. Other Republicans favor cheap labor, or want to court Latino votes, or whatever, and so don't want to crack down on the illegals that are here. In some cases, they don't even support a wall.
When Trump insulted Mexicans, it was a signal to a lot of people that he wasn't bound by political correctness, and wasn't afraid to offend the Latino vote. To those folks, this meant that Trump's promises to build a wall should be believed more easily than those of other politicians. He already alienated any latinos for whom that was a big issue, so he really doesn't have a reason not to follow through now. I think there's probably some validity to that POV.
What I dislike is how those Republicans who were in Congress and did fight for more border security are being trashed by Trump supporters. It's not their fault that voters didn't send more like-minded people to Congress, and even The Donald is going to need Congressional support to make significant changes.
I think it's sometimes forgotten that Bush and the "GOP-E" did actually authorize the first 700 miles of that wall, and did pass legislation to double the number of border agents. It wasn't like they did nothing about the issue when they had the majority. They got the ball rolling.