I think it’s a little more nuanced than that. They are against things that would lessen the collective bargaining power of those in their union. This is the whole point of unions, to collectively bargain.

If those immigrants were forced to join the union upon entering the U.S. and entering that sector of work, I don’t see the union having a problem with that. The issue is that would lead to those immigrants and all other members of the union being paid more, which is a no-no for the billionaire class.

So they’re not anti-immigrant. They’re against billionaires abusing immigration to pay people less.

That's not true. The MLBPA (baseball players) is definitely not anti-immigrant.