“Therefore, the electors are already partisan party voters who will not be forced to vote against their will. They would, however, be voting against the will of the people of their state.”
If the slate of electors are forced by legislation to vote for the national popular vote winner instead of their party’s candidate, then I would think they’re being forced to vote against their will.
There is a Republican slate and a Democrat slate. If the state goes to the Republicans, then the Republican slate is sent to the Electoral College. If the state goes to the Democrats, then the Democrat slate is sent. The Republican slate will enthusiastically vote for the Republican candidate, and the Democrat slate will enthusiastically vote for the Democrat candidate.
It's not one single non-partisan slate that gets sent with orders on how to vote.
The candidates' names are just proxies on the ballot; the people are really voting for Electors. It's just a convenience to keep from having 110 electors on the ballot with instructions to vote for 55 (if you're in California).
-PJ