Interesting, I don’t doubt you. I know what has been called the “Migra” by Mexicans has been around for a long time, at least early ‘60s, when the Braceros program was around. I’d think the Migra was still a national agency, Naturalization?, I’m not sure.
Braceros was a big issue in the 50s. Up thru the 70s the AFL-CIO was strongly anti-immigrant (both legal and illegal). The Chicago machine was extremely anti-illegal Mexican immigrant and attacking Puerto Ricans for not having immigration papers.
It really wasn’t until the SEIU in the last 10 yrs that Unions have flipped... and likewise the Republicans flipped.
Historically both religious conservatives and Wall Street Journal Republicans have been pro-immigrant. “Let the free market decide.” Hannity used to ridicule Pat Buchanan as the only Malthusian anti-immigrant conservative... as witnessed by his dismal showing in both primary and 3rd party elections where he did worse than 3 other 3rd parties.
Conservatives being on the anti-free market side of immigration is a relatively recent event.