The Americans who would like to keep their jobs, not have to train their foreign replacements.
Double Flip Flop H1B https://www.washingtonpost.com/news/fact-checker/wp/2016/03/21/donald-trump-flip-flops-then-flips-and-flops-more-on-h-1b-visas/
Polish UNDOCUMENTED built his tower.
http://www.nydailynews.com/news/politics/donald-trump-signature-tower-built-polish-immigrants-article-1.2545330
If H1B gets your Irish up (although there are many cogent arguments that it shouldn’t — that it’s a symptom not a fundamental disease) then look at what Cruz wanted to do with them. Before flip flopping.