It may not technically be racism, but it is clearly stereotypical bigotry, which is equally odious.
Mexico will not build any wall, and the US may only extend the wall they already have around populated areas, but there will not be a uniform wall along the entire border. This is not a major issue, in any case. Trump has no real economic plan, and he lacks the ability to deal with Congress. He would be a disaster as president.
But he will never be president.
We will all get to see him throw a major tantrum, eventually.
It will be more amusing than Fonzie jumping the shark.