It strengthens it. Remember the Constitution says the state legislature decides how to assign their EC votes. It doesn’t have to have anything to do with popular vote, on any level. They can just tell electors how to vote. They could flip a coin. They could make it dependent on the weather. Or a sporting event. Whatever they want, however they want, just so long as it happens on the approved schedule. And this reiterates that the Electors have to do what their legislature tells them too.
Unless a state legislature passes a law that says the Electors of that state will follow the national popular vote. Then its perfectly legal in the eyes of all nine USSC judges.