Are there restrictions on who the Electors can vote for?
There is no Constitutional provision or Federal law that requires Electors to vote according to the results of the popular vote in their states. Some states, however, require Electors to cast their votes according to the popular vote. These pledges fall into two categories—Electors bound by state law and those bound by pledges to political parties.
The U.S. Supreme Court has held that the Constitution does not require that Electors be completely free to act as they choose and therefore, political parties may extract pledges from electors to vote for the parties' nominees. Some state laws provide that so-called "faithless Electors" may be subject to fines or may be disqualified for casting an invalid vote and be replaced by a substitute elector. The Supreme Court has not specifically ruled on the question of whether pledges and penalties for failure to vote as pledged may be enforced under the Constitution. No Elector has ever been prosecuted for failing to vote as pledged.
Today, it is rare for Electors to disregard the popular vote by casting their electoral vote for someone other than their party's candidate. Electors generally hold a leadership position in their party or were chosen to recognize years of loyal service to the party. Throughout our history as a nation, more than 99 percent of Electors have voted as pledged.
This is a good reason to keep up the legal pressure on Hillary Clinton. Having her indicted before the electors vote would be icing on the election cake.
It sounds like electors could change their vote, at risk of fines, but then Soros would be sending them a fat envelope for their trouble.
But while,
The U.S. Supreme Court has held that the Constitution does not require that Electors be completely free to act as they choose
Yet,
The Supreme Court has not specifically ruled on the question of whether pledges and penalties for failure to vote as pledged may be enforced under the Constitution. No Elector has ever been prosecuted for failing to vote as pledged.
And with a Supreme Court that can legalize homosexual marriage and the ACA, then there is not certainty that they would not uphold the freedom of so-called "faithless Electors."