There is a way to bypass the Electoral College without a constitutional ammendment.

[Statistical]

5. True some states won't sign however it only requires states totalling 270 votes.

One problem is that swing states directly benefit from the fucked up EC system. They get a disproportionate amount of federal funding, disaster relief, advertising, campaign promises, and campaign stops. It is unlikely any swing state would pass the compact no matter which party controls the legislature.