How do you stop the right factions from doing that? Stay out of the fight because the right factions are terrible? Like, 2/5s of the DSA right now is a way of deradicalizing folks back into supporting the democrats. It used to be almost all of the DSA, like how CPUSA is captured by democrats.
I think people are disillusioned by bourgeoise democracy and don't understand that the DSA has an actual democracy because they see DSA being shitty and assume it is irrevocably captured. The right faction aren't that connected to the democrats, it is more of a "notice me senpai" relationship where some of the leadership want NGO positions, and the right leadership's hold of their membership is really tenuous because they aren't actually invested in organizing their membership, they're interested in mobilizing to prove that they're good mobilizers to democrats, putting them at a massive long term disadvantage which we're exploiting.
dialectical materialism posits that qualitative changes occur through the accumulation of quantitative changes- for example, adding grains of sand will eventually produce a pile of sand- I think this runs contrary to what they're trying to argue though, so maybe I'm incorrect in what they're referencing.