So did you favor slavery staying intact a policy in the US too, or did you recognize that things can actually change warranting a change in policy?

In the 1700's and 1800's, the US was adding vast frontier land mass that needed populating.  We haven't added land mass to the US in over a century, yet we keep importing population by the millions every decade.  The US population in 1900 was 76 million.  Today it's 325 million, and soaring.

Stupidly not adjusting immigration quotas to reflect those dramatically different realities is, well, stupid.