That would be 2024
It's almost a given that the ticket will be Trump/Carson. Trump is planning on peeling away the disaffected black vote from the Democrats. Which will be easy to do with a pasty old white woman as their alternative.
Look at the polls. If they team up they have a lock on all the demographic blocs - excepting the Latino and Asian blocs. Trump is appealing to union members and the really rich are divided. The hedge fund guys will hate him but the corporate boards will love him with a 15 percent tax.
Hillary can't compete with that. But time will tell.