> The current system seems to generate a collection of second-class citizens

Poor choice of words. Illegals are not citizens. That's the whole point.

> have no recourse if they're exploited

The recourse is to go back. In the era when you could just immigrate to the US just by getting on a boat (before the Immigration Act of 1924), about 1/3 of immigrants went back to their home country if they did not make it in the US.

See:

> From 1908 to 1932, 12 million individuals migrated to the United States. Over the same period, four million returned to their source country.

-- https://www.sciencedirect.com/science/article/abs/pii/S00144... (you have to pirate it to view the full thing)

But now, the expectation of leftists is that the government is somehow supposed to help the failed immigrants.