 But now Trump has actually said, I don't know anything about these people, but I disagree with them. Now, which is it? If you don't know anything about it, how can you disagree with it if you don't know anything about it? 649. Conventional wisdom holds that vice presidents don't matter much either in elections because voters choose based on the top of the ticket or in practice because they have few assigned duties. But Joe Biden's choice of Kamala Harris in 2020 is shaping up to be a momentous decision now that the president might have to leave the race following you-know-what.