Yes, here's the topic again. Coincidentally I bumped into this video on YouTube. Its an interview of Reagan by W.F. Buckley in which Reagan very clearly defines what he means by "States Rights". So, put your dogs whistles away, and listen. I think it makes things pretty clear, but probably sets the history revisionists back a bit:
https://www.youtube.com/watch?v=6BuwYjbQOC8