I would say balance the ticket.
They are the people who are running for president.
The President selects his own running mate.
On the Democratic side: Joe Biden On the Republican side: Sarah Palin
Just Ron Paul, & Rick Perry?
Yes, the candidates running for president get to pick their own vice - president. After all, it has to be someone they get along well with.
I am guessing you mean electors for the presidential election. These people usually do not have their names on the ballot but there are sworn to vote for one of the candidates who is running president and whose name is on the ballot. So when you vote for a presidential candidate, you are really voting for his slate of electors.
Officially, the parties still select the Vice Presidential candidates. Unofficially, each Presidential candidate chooses his/her own running mate.
They are called the party's presidential ticket. Also the party's presidential nominees.
1800: The Constitution then made no distinction between Presidential and Vice-Presidential candidates, and Jefferson found himself in a tie with his running-mate, Aaron Burr. After several ballots the House of Representatives chose Jefferson as President.
A candidate that is running for President receives their nomination at their party's convention. This is a meeting that is held to announce the results of an election.
Advisors select and choose a vice president.
John Adams and Thomas Pinckney were both technically presidential candidates and both belong to the Federalist party. Pinckney was the intended running-mate to Adams.