I wouldn't exactly call this "fickle", they consequently hold objectively reactionary posititions, as explained by Stalin in "Foundations of Leninism", just the history moved a little too fast this time XD
If you think of it, it's pretty impressive how liberals always manage, without even a sliver of understanding, recognize which side is objectively reactionary and follow it.
I know so many liberals in my personal life who claim they wouldn't have supported Jim Crow or Confederates if they were alive in previous eras. They absolutely would have.