Why and how is the Vice President elected in U.S?

Question

1. Why is the Vice President elected in the US? Why isn't he chosen by the President like any other secretary? Is there any important reason why the writers of the Constitution made that choice? 2. How is the Vice President elected in the actual bi-party system? Is possible to have a VP from party B even if the President is from party A?

Answer 1

The President and Vice-Presidential candidates run as a single ticket, together, once the Presidential candidate wins the party nomination. So in the general election, a person voted for the Trump/Pence ticket or the Clinton/Kaine (or one of the other party tickets). I guess technically a Presidential candidate could choose a member of another party as a running mate, but I seriously doubt one would, at least not one from the two main parties. I've thought it would be interesting if a candidate from the Green party or one of the other minority parties chose a really strong Democrat Republican as their VP. Like, if one of them had chosen Bernie Sanders, could she have gotten a lot of the Democratic votes from people who didn't like Clinton?