The person who came closest to winning as a third party was a racist former VP running on a campaign of upholding slavery despite any ruling SCOTUS made. Look it up. No alternate candidate has any hope of winning.
I bet it is easier to get to leftism under an administration like Biden, dead wrong but “students have a right to protest,” vs. any Repub, dead wrong and also “send in the National Guard to get these students” or “nuke Gaza.”
Also the Repubs did an insurrection and want to stop votes from counting ever again.