Michael Morley has posted this draft on SSRN (forthcoming, Harvard Law and Policy Review). Here is the abstract:

The National Popular Vote Compact requires member states to appoint presidential electors based on the outcome of the national popular vote in presidential elections. It enters into force when states holding a total of 270 votes in the Electoral College adopt it. The Compact has already progressed more than 2/3 of the way toward that goal. If it enters into force, the Compact will fundamentally change the nature of presidential elections without a constitutional amendment.

The Compact suffers from numerous constitutional flaws that have not been addressed in the literature. It violates the right to vote of member states’ citizens, by requiring those states to appoint presidential electors based on national vote tallies in which the votes of a member state’s eligible voters are diluted or even overwhelmed by votes of other states’ citizens who are ineligible to vote there. The Compact also violates the Equal Protection Clause as applied in Bush v. Gore because it requires all votes cast throughout the nation to be tallied together, even though they were cast under fifty-one different electoral systems, with materially differing voter qualification standards, voter registration and identification requirements, rules for counting and recounting ballots, and even policies on whether ranked-choice voting is permitted. The Compact also violates the Constitution’s implicit structural protections by undermining the special protection that the Electoral College affords smaller states and allowing a cabal of states to decide among themselves who the President will be, rendering other states’ electoral votes irrelevant. Finally, the Compact violates the Presidential Electors Clause by purporting to limit the inalienable plenary authority that the U.S. Constitution confers directly on state legislatures to determine the manner in which the state will choose its electors.

Even if the Compact were constitutionally valid, prudential and practical constraints counsel strongly against it. The Electoral College allows a presidential election to be resolved as a series of fifty-one discrete, parallel contests, rather than a single national election involving over 136,000,000 votes cast at thousands of locations. The Electoral College’s compartmentalization makes the system manageable, confines the scope of recounts or post-election litigation, and limits the consequences of any natural disasters, mistakes, or even fraud that may occur. Due to the geographical breadth of our modern nation and size of our population, the ability to elect a national leader through dozens of smaller, limited elections has become a largely inadvertent gift from the Framers that we should not squander.