You better believe when the day comes that the Republican nominee receives the plurality of popular votes, the New York and other Democrat legislatures will meet in emergency session shortly after Election Day and change the law to their favor.
An escape clause was written right into the bill they pushed here in Michigan. They could withdraw from the agreement for any reason (If it looked like a GOP win) 6 months before an election.
Sadly there are republicans who pimp this crap like Fred Thompson.
Once the Census-derived electoral college apportionment is replaced by popular vote counts, the states will gin up their numbers by reducing the voting age to 12 and granting the franchise to non-citizens. Election night will be an auction-like frenzy as state election boards discover hundreds of thousands of absentee ballots yet to be counted.