What is a significant requirement for replacing the electoral college with direct election?

The correct answer is that a constitutional amendment is required to replace the electoral college with direct election. This is because the electoral college is established in the U.S. Constitution, specifically in Article II, Section 1. Any change to how presidents are elected would necessitate an amendment to the Constitution itself. This requires a rigorous process—approval by two-thirds of both the House of Representatives and the Senate, followed by ratification from three-fourths of the state legislatures or conventions.

While the other options suggest significant changes or requirements related to the process, they do not align with constitutional law. Abolishing state power would undermine the federal system established by the Constitution, and implementing popular vote tallying per district would introduce complexities not supported by the current framework of national elections. Additionally, obtaining agreement from all states would be impractical, as the interests of states vary significantly. Therefore, the only viable and constitutional method for such a change is through a formal amendment.