Are they running anyone in elections they might actually win? I might vote for a party like that for mayor or something. But I wouldn’t even vote for them for state house representative unless they were well known enough in my state that they might actually win.
‘Third’ parties in this country can show themselves as serious if they try to establish themselves from the bottom up. If all they do is run for president and occasionally Senate or House, then they show themselves as unserious parties which are probably nothing more than attempts to siphon votes that might have gone to a real candidate.
I don’t know odds, I’m not much of a gambler. You gotta start somewhere though and winning isn’t all that matters: at the presidential level losing parties’ turnout determines their ballot access, event presence, access to funds and media and obviously how much you hear about them.
At the state and local levels there are Byzantine other benefits to having some percentage of the vote that vary wildly from place to place.
So its worth it to vote for a small candidate even if they lose because it can have big effects down the road.
Psl runs candidates at lots of local races, especially in California because that’s where they started.
Of course, if your main worry is having voted for a candidate that can win: good news! Psl can win every race it has a candidate in as far as I know. People were saying that they didn’t have enough ballot presence to tip the electoral college but they were wrong!