Dem
50
GOP
50
In addition to Kamala Harris and Donald Trump, four minor candidates are on the ballot in multiple states (and a few very small parties are on the ballot in a couple of states). The major minor candidates on the ballot in many states are Robert F. Kennedy Jr., Jill Stein of the Green Party (GP), Chase Oliver of the Libertarian Party (LP), and the independent Cornel West (I). Here is a map showing where they have made the ballot:
Who do the minor candidates hurt? It's a mixed bag. Kennedy and Oliver generally hurt Trump; Stein and West generally hurt Harris. Kennedy is on the ballot in Wisconsin and Michigan. Oliver is on the ballot in the most places, including all the swing states. Stein is on the ballot in all the swing states except Nevada. West is on the ballot in Wisconsin, Michigan, and North Carolina.
Kennedy and Oliver could hurt Trump in the northern states, especially since the LP often gets at least 1%, often more. In 2020, the LP got 1.2% of the total vote. In an election as close as this one could be, 1.2% could be enough to swing a state. In 2020, the GP got 0.26% of the vote, but the candidate then was Howie Hawkins, a total unknown. In 2016, Stein was the GP nominee and she got 1.07% while the LP candidate got 3.3%.
Do such small numbers matter? Well, in 2020, Joe Biden won Georgia by 0.23% and he won Arizona by 0.30%. By comparison, Wisconsin was a relative landslide with Biden winning by 0.63%. So, to answer the question, "yes." The Democrats, at least, have taken notice and are now running an ad attacking Stein as a spoiler:
Stein knows very well that she is a spoiler because she probably caused Hillary Clinton to lose the 2016 election. She's fine with Trump winning due to its educational value. She wants to teach the Democrats a lesson: If they don't adopt the GP platform, they will lose. If Harris can win without adopting the GP platform, that neuters the GP. The ad basically says that a vote for Stein is a vote for Trump. While Stein doesn't care if Trump wins, some of her supporters probably do and an active campaign to paint a vote for her as a vote for Trump could dissuade some of them.
So far there are no ads against Cornel West, probably because he is less well known and is not a candidate of any party (unlike Stein and Oliver). He's just on a big personal ego trip. If he were interested in policy instead of just glorifying himself, he could have gone to Stein and offered to drop out and support her in return for the #2 slot on her ticket. So far, the Republicans are not running ads against Oliver and certainly not against Kennedy, who is now a Trump supporter because he is under the illusion that Trump might offer him a good job in his administration. It is possible that Trump might offer Kennedy the ambassadorship to Nauru, an island nation in the middle of the Pacific Ocean consisting entirely of bird poop, both as a symbolic gesture and to get rid of him. A better job than that, probably not. (V)