What would my purpose even be? Can any good come of it for the left?
Best: Joining a burgeoning revolutionary communist movement. Doesn't really exist in the United States at the moment, so probably not on the table for you.
Pretty good: Joining a party with communist roots, could be PSL, PCUSA, SAlt, or a handful of others. It's "pretty good" in theory, but internal politics can actually get in the way of actually getting anything done, depends on your branch. You might not even have a local branch at all which leaves you at square one.
Good: Joining DSA , particularly if there is an active Marxist caucus at your local branch (if not, start one). They have people power on a national scale, and it can be more accessible if you have friends who are interested in getting politically involved. The stipulations for the above options also apply (internal drama and existing in your area).
Fine: Joining your local Democrats. It's not "good", since it's a bourgeois party that doesn't do a single thing outside of electoralism. There is a slim chance that you might do a single good thing though (very slim, establishment liberals are very protective of their own, even at the local scale). Better than nothing I guess, cause at least you'll have a regional branch. We will call you a liberal if you talk about it on here though, and you'll have no rebuttal.
Anyway, start at the bottom of the list, and work your way up if any of the others are available, the Democratic party should be a last resort, and you should keep it in perspective.
I think if you want todo political work, you'd rather get involved with a group like DSA or Sunrise Movement that plays an inside-outside game. The Democrats are the graveyard of social movements. They care only about winning seats and enriching donors. Anytime the Democrats do something good - and yes, that sometimes happens - it's because they're facing extreme pressure from outside groups. So I think it's much more useful to organize with those outside groups, and DSA and Sunrise are easily the best. Those groups will organize for good Democrats and lead protests against shitty Democrats. If you organize within the Democratic Party, you won't be able to protest against corporate Democrats. You might even have to work for corporate Democrats against leftist primary challengers.
To show how futile changing the party from within is, look at Obama 2008. Obama's 2008 campaign had the single best organizing apparatus of any campaign in modern US history not run by Bernie Sanders or Donald Trump. As soon as Obama won, he merged his organizing apparatus into the DNC and basically squashed the grassroots of the party while filling his cabinet with corporate ghouls. If you organize with the Democrats, that will happen to you.
Howewer, I don't think "pushing the Democrats left" is as hopeless as some people on this forum make it out to be. The Biden admin sucks, sure, but it is also an unobjectionable fact that Biden's administration is far more progressive than Obama's. That's not because the Democrats have suddenly became less shitty people, it's because there are groups outside the Democratic Party who can threaten corporate Dems with primary challenges. Progressives in the House and Senate have spiked the worst impulses of Biden's term so far. Monsters like Rahm Emanuel and Larry Summers have gone from major players to fringe figures in the Democratic Party over the past 5 years because of outside pressure from the left.
You can't push the Democrats left from within the party, you have to threaten them from outside the party and extract concessions. Groups like DSA and Sunrise do as good a job of that as any. Organize with them, not with the lanyards.
I actually don't think it is a horrible idea if you are doing it as part of a larger group of people.
The Democratic party is a capitalist party. If I was you I would not get involved with any organization that does not have "socialist" in the title or as its main thrust.
