Has this been challenged for constitutionality? It disenfranchises electors and the voters both.
There is no Constitutional prohibition against disenfranchisement in a Presidential election. Voting is a privilege granted to you by States, not a federal right. However, there is a penalty for it in Amendment XIV. So the Constitutional challenge would be this. By handing the election of state electors over to the entire country, a State will have effectively diluted the voting power of each of its citizens (i.e. partial disenfranchisement). And according to the 14th Amendment, their representation in Congress should be reduced accordingly. So Virginia's representation in Congress would be reduced from 11 seats down to 1.
