In choosing a President, standard-bearers for each of the major parties bubble up to the top through an extended process of caucuses and primaries over a period of months. The contenders then essentially campaign in 50 separate state elections, vying for a majority of Electoral College votes that are apportioned according to state population. Checks and balances everywhere you look.
What about choosing the Vice President? You know, the person who’s a heartbeat away from the most powerful office on earth? Oh, one person makes that decision unilaterally.
The VP is not elected or confirmed in any meaningful way — theoretically the party convention could reject a VP candidate, but it won’t happen, and even if it did, that’s not a choice, that’s a veto. The VP nominally is elected along with the President — but it’s a package deal, the votes really are being cast for the top of the ticket.
One person’s unilateral decision. Even an Assistant Secretary of the Interior has a more rigorous vetting process — the Senate has to confirm the choice.
Originally, whoever came in second was named the Vice President. So when John Adams defeated Thomas Jefferson, Jefferson became VP. Then Jefferson ran against his boss four years later and ousted him. Bizarre as it sounds, I almost think that’s a better system than what we have now. The Secret Service might have to protect the President FROM the Vice President… but if the VP moves up, at least the incoming President would have been a strong vote-getter in a national election.