And they were not "conservative" in any sense except trying to "conserve" slavery. The elite intellectual "progressive" democrats of the time were also the most racist. They were the ones, for instance, that pushed eugenics for blacks (Planned Parenthood), and racial superiority based on scientific data:
https://www.washingtonpost.com/opinions/the-liberals-who-lov...
On the other hand, more Republicans voted for the civil rights act as a percentage than Democrats: https://www.wsj.com/articles/SB1041302509432817073
You're not doing so hot with your example.