Vance is together with trump running as his second. Kennedy was an independent running against trump and then joined him, but didn’t file his withdrawal soon enough so he’s still on the election ballot as an option running against trump. Basically, you can vote for him in a few states which might keep his followers from swapping with him and costing the conservatives the state.
Probably out of some sense of getting the rest of the school to learn a lesson, and creating anger at the racists. Probably misguided.