President Andrew Jackson and his supporters definitely fit this description of “liberal racists.” I feel like Jackson would agree with the modern progressive left on a decent amount of issues.
Don't forget all the Southern segregationists who were also ardent New Dealers (and major progressive reformers in the years prior to the 1930s); racism is often thought of as being purely on the political right, but it's a little more complicated than that - just look at the PQ or Bloc here in Canada.
What's the story with PQ and Bloc?