All they need to do is initiate a new ‘bracero’ program, allowing them to work here & return home.
If the R’s won’t do that, then they need to have a loooong period of time where they may work but do not have the rights of citizens (no voting). And before they become citizens they must pass a very strict test on American history & the constitution & they must be able to speak the English language fluently. Failure on any of these means they must re-patriate to their home country. No citizenship.
Yea, I know. I’m dreaming.