Is National Popular Vote Interstate Compact Constitutional for electing POTUS?

[True Federalist (진정한 연방 주의자)]

It's constitutional, but I doubt it will ever get the necessary level of support to go into effect, and it would be vulnerable to collapse if states withdraw, which they may well do.

[True Federalist (진정한 연방 주의자)]

I don't think it's implicitly a compact. There are provisions of the law that passively cause it to come into effect when enough other states have passed similar measures, but there aren't any actual agreements between state governments.

There's the July 20th lock-in date.  That's not enforceable unless it is a compact.

[True Federalist (진정한 연방 주의자)]

While I think the NPVIC is a kludge, I don't think OMOV concerns really apply.  Because the compact only applies if there are enough electoral votes to determine the winner, popular votes for president are effectively being counted only once.  The difficultly is when we get a really close result in the popular vote.  It effectively means that the brouha we had in Florida in 2000 would get repeated nationwide and if some states differ in whom they believe won the PV, we could end up with a massive CF.

(Note: OMOV would apply if the NPVIC kicked in before reaching a majority of the EV.)

[True Federalist (진정한 연방 주의자)]

muon, your whole argument is based on hypotheticals that have no relation to reality.  The way the NPVIC is structured, so that it only goes into effect when it selects a majority of the EV, there are no OMOV concerns. Every individual's Presidential vote counts exactly once, even in States which are not part of the compact because their State's EVs are irrelevant to the selection of a President and a Vice-President.  Your concerns might have some validity if the Electoral College had any other function than electing a President, but it does not.

[True Federalist (진정한 연방 주의자)]

First off, the sole reason for the existence of the Electoral College was to have a duplicate Congress whose only purpose for existing was to elect a President while preserving an 18th century notion of separation of powers by having the President not be elected by the real Congress.  That it gives small states excess power in electing the President is an incidental effect and any effect that NPVIC might have diluting such power is not a reason to find it unconstitutional.

Second, small states don't have power under the current system.  Swing states do, and the larger the better.

Thirdly, states will still retain individual power, as unless the NPVIC gets a level of support that indicates passing an amendment to make the national PV winner be the overall winner would be doable, states will be able to threaten to pull out and wreck the NPVIC system.  So clout will be available with larger states having more chance of having such power, just as the current system does.