I am working through Lenin Rediscovered right now and the DSA base smacks of the group Lenin spoke to then: a disorganized collection of ideologies including, as you said, oppurtunists, but also economists and recent tailist tendencies post-Mamdani. That does mean they are a large base that is most likely to be receptive to ML/MLM ideology and a reasonable group to try to flip vs the working class, which seems to have failed any push, even with the amount of basic education on socialism they have (a la mantras like “there’s no ethical consumption under capitalism”) and the imperialist tendencies (now again in the spotlight thanks to Trump).