Nope, he used to be active in the World Workers Party, but he left years ago. He pushes for going “out of the movement, into the masses”, being generally dissatisfied with all the US socialist parties and views the movement as having been going nowhere. So nope, he’s not in a ML party right now and it doesn’t seem like he’s going to be either.

We’re not some Trot party

Doesn’t the PSL have Trotskyist (Marcyite) origins?