Is National Popular Vote Interstate Compact Constitutional for electing POTUS?

[zorkpolitics]

There is another argument that could be made National Popular Vote Interstate Compact is unconstitutional: it infringes on the political power of the small states.  Although we don't think often about the relative political power between the states, this was of extreme interest during the drafting of the Constitution.

The constitutional convention explicitly considered how to allocate power between the states in the Federal Government.  They decided to give unequal political power to the small states in two ways:
1) Each state has 2 Senators, regardless of population (Article I, section 3).
2) Small states have extra weight in the Electoral College, since each state is awarded a number of electors equal to the sum of Senators and Representatives, and not just the number of Representatives (Article II, section 1).

The extreme importance of giving small states extra political weight is confirmed in Article V. This article requires unanimous consent of all the states to change the allocation of Senators, rather than the regular amendment process to change any other part of the Constitution, which requires "only" 3/4 of the states to pass an amendment.

Currently citizens in the smallest states have more than twice the political power in the Electoral College as citizens from large states.  In the 2012 election, the eight smallest states (those with 3 Electoral Votes) averaged 115,000 votes per electoral vote.  In contrast, there was on average 255,000 votes per Electoral Vote in the 6 largest stated (those with 20 or more Electoral Votes).

Clearly any attempt to implement the National Popular Vote Interstate Compact will reduce the political influence of the small states in the Electoral College, it would be interesting to see if the Supreme Court would take such a case.....