I disagree with your slavery/cheap labor/citizenship premise. Before the courts began to misinterpret the 14th, it seemed to work. Granting citizenship rewards bad behavior IMHO and teaches the 2nd generation the wrong thing.
Unfortunately, Citizenship almost doesn’t matter today...seems as if non-citizens can already access most of the good things America has to offer.
Back then they had birthright citizenship.
If you are arguing to the situation prior to the 14th, slavery is a huge, huge blight. The recognised birthright citizenship but only if you were white and male. Radical at the time, as the suffrage was much more limited in the UK.
Things are different now. So long as there is demand (welfare checks and employers willing to hire cheap labour), there will be a supply of illegal immigrants.
Getting rid of birthright citizenship isn’t going to change this one bit. Only now, all those babies who are ‘anchor babies’ will live with freedom in America, only just not as citizens of America.
Does that sound like a good thing to you? Getting generations of these folks, none of whom are citizens, none of which matters in their daily lives as the checks flow?
You think that the government is going to crack down on people smugglers if the people that are being smuggled in won’t count as citizens? Will they even care anymore?
“Granting citizenship rewards bad behavior IMHO and teaches the 2nd generation the wrong thing.”
As opposed to not granting them anything and letting them stay?
“Why does being a citizen matter when the checks don’t care?” Answer, very little. “Why should we bother to learn english?”
The current laws aren’t being enforced. In order for any of this to be effective the current laws must be enforced.