The only reason not to do so is the vanishingly rare chance that democrats turn a red state, which is basically the exact same argument they use to tell people to vote blue no matter who, but more compelling because it's not typical genocidal am*rican politicians they're voting for.
What are they going to do? Tell you they want to vote for a war criminal on principle? The positive political pressure of having a somewhat popular socialist party far outweighs the small chance democrats could have won (and this is even from their perspective, that the democrats winning would fix everything somehow)
You can pretty much convert any liberal or conservative that’s willing to learn from books as opposed to podcasts and memes and out of context graphs. It’s just annoying that there aren’t many of those people around.
But yeah, liberals can be converted. I just have less patience for it because they’re usually incredibly condescending about shit they have little to no clue about, and it takes pushing through that arrogance to actually convince them to read about these things in depth enough to actually understand them.