The word “progressive” has meant Communist for many decades.
The Communists believed and believe in a world of “progress” where everybody lived happily ever after...
as their slaves.
Yes,
They are “progressive” because Marx analyzed the human history and figured out that communism is where the humanity heads.
So “progressive” are trying to speed up this way to communism, while conservatives are trying to slow this Marxist “progress”.
Marx actually missed the really old history. Communism is really return to stone age. But he wrote all his stuff 150 years ago, he had no idea how stone age worked.