The National Popular Vote Interstate Compact wants to put together a coalition of States whose Electoral College votes aggregate to 270—the minimum majority required to elect the President and Vice President—and which coalition then would allocate their Electoral College votes to the national popular vote winner, instead of to the popular vote winner of the particular State.
This is a naked attempt to defeat the purpose of the Electoral College as it is constituted in our Constitution.
This is what Art II, Section 1, says about the Electoral College: