The Tenth Circuit Court of Appeals is right; there is constitutionally no way to compel the vote of a presidential elector.  All one need do to see that this is the correct result is to look at the operative constitutional provision regarding the appointment of electors:
“Each State shall appoint, in such Manner as the Legislature thereof may direct, a Number of Electors, equal to the whole Number of Senators and Representatives to which the State may be entitled in the Congress: but no Senator or Representative, or Person holding an Office of Trust or Profit under the United States, shall be appointed an Elector.”  (U.S. Constitution, Article II, Section 1)
“The Electors shall meet in their respective states, and vote by ballot for President and Vice-President, one of whom, at least, shall not be an inhabitant of the same state with themselves; they shall name in their ballots the person voted for as President and in distinct ballots the person voted for as Vice-President, and they shall make distinct lists of all persons voted for as President, and of all persons voted for as Vice-President, and of the number of votes for each, which lists they shall sign and certify, and transmit sealed to the seat of the government of the United States, directed to the President of the Senate….”  (Id., Twelfth Amendment)
There is no ambiguity here. The manner of choosing electors is determined by the state legislatures, but the presidential votes themselves belong to the electors. If any doubt remains, there is Alexander Hamilton’s description of the process in Federalist No. 68:
“It was desirable that the sense of the people should operate in the choice of the person to whom so important a trust was to be confided. This end will be answered by committing the right of making it, not to any preestablished body, but to men chosen by the people for the special purpose, and at the particular conjuncture.
“It was equally desirable, that the immediate election should be made by men most capable of analyzing the qualities adapted to the station, and acting under circumstances favorable to deliberation, and to a judicious combination of all the reasons and inducements which were proper to govern their choice. A small number of persons, selected by their fellow-citizens from the general mass, will be most likely to possess the information and discernment requisite to such complicated investigations.” 
Therefore, the decision of the 10th Circuit is not an outrageous assault on the effectuality of the popular will, but sound constitutional exegesis. And it may be timely. Hillary Clinton received, nationally, 2,868,691 more votes than Donald Trump in the 2016 presidential election  (though no candidate won an outright majority), and one might reasonably suspect that we’re going to see an increase of such outcomes in the future.
While there may have been wisdom in constructing a presidential election system where a “small number of persons, selected by their fellow-citizens from the general mass,” who would “be most likely to possess the information and discernment requisite to such complicated investigations,” things simply haven’t played out that way. There is no evidence that the electors actually chosen are the best and brightest among us, and one suspects that the general temperament of the country wouldn’t tolerate confiding the election of the President to a select few. We’d need the sort of non-partisan country envisioned by the constitutional Framers for that to work as intended in any event.
But a system where the President is increasingly elected by a minority of the voters is going to eventually present its own problems. The violation of the one-person-one-vote principle is manifest, and states that continuously find their populations frustrated by the selection process might start giving serious consideration to secession.
The recent Tenth Circuit case, particularly if it is upheld by the Supreme Court, should serve as a wake-up call that constitutional reform is critically necessary. The practical obstacle is that the system currently in place served certain partisan interests, and we have learned not to expect a principled look at the long view from such quarters.