Libertarian Party has been gradually weakening and had a massive internal schism in 2022 leading to sections of the hardliners defecting to Trump and many of the moderates ending up with RFK Jr(who dropped out to endorse Trump). Nominee is a Left Libertarian and for reasons they weren’t even listed as a third party candidate on most polls or polling conglomerates until September as they weren’t in the Top 5 which further hurt their outreach.
Green Party has bounced back as they got Jill Stein’s namecred and benefited from being above the Libertarians in the rankings thanks to RFK.
Constitution Party(hard right) has been bleeding support since the Obama era, most of them have been leaving for Tea Party Republicans and the remainder is being siphoned off by Peter Solski’s Moderate Christian Party.
The PSL is the fastest growing third party right now, overtaking the Constituion Party in 2020 for 3rd place and set to potentially overtake the Greens and Libertarians if they continue infighting and bleeding support.
Cornel West exists.
I mean, it’s a factor in how much of which party they siphon from
Tbh, the only time any alternate candidate did enough to matter in that regard was Perot. Before that? So far back as to be irrelevant to modern US politics.
Green can’t, the old libertarians couldn’t, the socialists can’t. Nobody that would jump ship from the big two would jump to those instead of just going independent as a candidate, and voters have shown repeatedly that they don’t siphon worth mentioning.
I dunno, maybe if someone like Sanders jumped to one of them back when he was a viable candidate, it could have pulled enough democrats to matter. Trump probably could but there’s no way he’s abandoning the party he’s fooled into thinking he is a part of.
But there’s simply nobody in the other parties that’s remotely interesting to swing voters at all. The far right is maybe splittable from the Republican party, but not while trump is their guy. The far left isn’t going to be siphoned off because they don’t vote for either of the big two to begin with. There just aren’t that many people that will avoid voting democrat in general and not just abstain. With Kamala pushing hard, and being a viable (if distasteful for mid-left and abhorrent to far left) candidate, it sure as heck won’t happen for the presidential race.
The same is essentially true for congressional seats.
With FPTP voting, alternative parties are dead in the water as long as nobody splits the big two from within.
It can matter in swing states if it comes down to 4 digit margins. Florida in 2000 for example, or New Hampshire in 2016