will preserve the usa's identity as a european majority country
It is too late for any of this. Less than 50% of the children born in the United States are non-Hispanic White. So even if there is zero net immigration, the United States will be majority non-white by 2030 (if not sooner). Trump might be able to slow this transformation, but by no means he will be able to prevent it from happening in the future.
America is a majority immigrant country, so there's nothing new going on now or in 2030...
Seriously you guys are debating if America is a race country or not? My goodness all those confederates that didn't die in the civil war DID actually spawn millions of you.