Its the "pull up the ladder" phenomenon. You even see it in places you wouldn't expect, like US workers opposing student loan forgiveness proposals because they had to pay, and want to make damn sure everyone else has to go through the pain that they did.

I watched an immigrant buy the house across the street and turn it into a compound, build a business with undocumented folk he kept in campers outside his house, and now that its established he ditched the campers, flys Trump flags, and advocates for mass deportation.

The "I got mine" mentality is strong.