It’s not “leftist” necessarily, but all leftists should inform themselves about the Russian Revolution IMO, which is covered by season 10 (the final and currently ongoing season) of the Revolutions|^Spotify podcast.

Mike Duncan isn’t explicitly leftist or anything, but he really does his homework and portrays things in a really neutral way. Whether or not you are a big stan of the USSR and what came after, the Russian Revolution was the most successful attempt at overthrowing capitalism (to an extent), and any future movement should learn from and analyze all aspects of what happened in those years.

Citations Needed|^Spotify is my other favorite with their in-depth media criticism (if you like Chomsky’s stuff, you’ll probably like what they have to say).