Fun fact: a lot of the CPUSA members are pretty much just Democrats. The premier revolutionary organization in the U.S. would probably be the PSL.
At least you could take the CPUSA seriously in its prime (1919-1948) when they actually nominated eligible candidates, unlike the PSL. They are an embarassment.
Their point isn't to get elected. They're the sort of revolutionaries who reject participation in bourgeois politics. They seem to mostly just run candidates as a tool to raise awareness.
They get 3 new people interested per election
Yeah, personally I don't see how what they're doing is supposed to work -- a fluff campaign for president that doesn't even have eligible candidates.
But I do think the PSL is neat. The CPUSA has a cool site, but as I've already said they're not all that revolutionary anymore.