Depends heavily on chapter from what I've seen. If they're the only organizing in your area you'll likely find a chapter undeveloped enough where if you aren't irritating you could easily influence it's political character. Watch out for SMC and Groundworks caucuses, those are the ideologically committed right-of-Menshiviks. NYCDSA is ran by their coalition for example. If your local chapter is ran by them, you're probably cooked. (Follow-up reading on this: https://cosmonautmag.com/2026/01/dredging-the-southern-earth-4-years-later)
Expect chauvinism and opportunism, comes with the territory, catch people on the way in and encourage political development towards your ideas, if you're luckily you'll find some somewhat ideological allies(Maoists/MLs -> Neo-Kauts/Trots from closest to furthest. Libertarian Socialists are somewhere in there depending on how much you like anarchism).
Godspeed and good luck.
NGL, from what I've seen you're essentially dealing with an entirely different org depending on what chapter you get.
One nearest to me has pro-zionism as grounds for chapter expulsion.