All but the nominee resolve NA.

The nominee resolves YES if he/she wins the overall election and NO if someone else wins.

First nomination counts. If Biden gets nominated everybody else is NA. If Biden later withdraws, he resolves NO. Followup does not matter.

Arbitrate with /Tetraspace/if-joe-biden-becomes-the-democratic

There is also /marketwise/will-a-republican-win-the-2024-elec

Close date might be extended if election results take longer.