The important thing to notice in the above amendment is that it does NOT say how electors get to be electors. That is determined by STATE law.

I believe that in ALL states, electors are first nominated by their political parties. Then MOST states require that ALL their electors must come from the same party whose presidential and vice-presidential candidates receive the most popular votes in that state. The exceptions are Maine and Nebraska, where one elector is chosen for each congressional district, and two more electors are chosen for the state as a whole.

I suppose then, that each party in each state has its own rules about how electors are chosen to represent the party. Generally, the public and the news media take no notice of this process. I don't recall ever seeing a list of the electors' names. We take it for granted that the parties nominate people who are guaranteed to vote for the candidate their party endorsed. As long as this is true, the electoral vote is entirely predictable once you know the popular vote for each state (except that in Maine and Nebraska, you need to know the vote in each congressional district). There have been a couple of instances of "faithless" electors who voted for somebody else, but since it wasn't enough to change the outcome of the election, hardly anybody paid attention.

There has been some speculation about special situations that might induce electors to change their votes. What if the winning candidate died after the general election but before the electors cast their ballots? It seems that then the electors would have a real choice to make.

What if Nader had won one state? The Green Party electors would have nothing to gain by casting their ballots for Nader, but they might have something to gain by striking a deal with one of the other parties.