Although it is a matter of opinion, and there are probably many contrary opinions, my opinion is that progress for the National Popular Vote Plan is good for minor parties and independent presidential candidates. My opinion is based on the idea that if the National Popular Vote Plan got quite close to being implemented, the various state legislatures would mostly then be willing to pass a constitutional amendment to eliminate the electoral college. And that amendment would also bring about congressional authority to write one ballot access law for presidential elections. For example, U.S. Senator Bill Nelson’s pending constitutional amendment specifically authorizes Congress to do this.
I believe that a single ballot access procedure for presidential elections for the entire nation would be an improvement over the existing system. Minor parties and independent presidential candidates would no longer be at the mercy of states like Oklahoma, North Carolina, Georgia, and Indiana, states which are so severe for ballot access that Ralph Nader has never managed to appear on the ballot in those states, even though he is the person who came in third in 2000, 2004, and 2008.