Only 10-15 states might have a passing interest in something like this, but it will have no bearing on the other 35 states. It might actually compel some purple states to vote red in future elections. The politicizing of the electoral vote might offend some people. Even blue state types.
I do not think any legislature will pass a law that would allow for their electors to vote differently than what the state popular results are.
Ok, maybe California.
If democrats had any brains they would not mention the popular vote idea for another hundred years.
Of course they have no brains, so we will continue to hear drivel like this unfortunately.
The states involved say their pact is binding once states representing 270 electoral votes adopt it. Congress has power under the US Constitution to regulate interstate compacts.