Trump is on the record extensively as being very pro H1B (probably spurned on by Musk, Zuck, and Pichai). Because many of these workers can be overworked without complaint for lower compensation than American workers.
It's about protecting blue collar workers. H1Bs damage the "coastal elite". Illegal immigrants are the threat to blue collar workers, and look at his stance on them.
It's impossible to not see that Trump is trying to bring back the 1950's rust belt all American factory family.
It's never been about protecting Americans...