He is a registered democrat. Leftovers of the party that had Scoop Jackson, Moynihan, Nunn and Zell Miller. You could have a reasonable debate on issues you disagreed with those people. I am sure JFK would feel quite uncomfortable in the Dem party now as well.
A Scoop Jackson Democrat, JFK, or VDH are more conservative than the GOP/RNC.
The old Reagan quip( modified ), “I didn’t leave the Democrat Party, it left me......and took the GOP with it”