There's nothing in the Constitution that says they have to do what a majority of the people want. In fact, it's designed so that that doesn't happen. Don't blame me. I didn't write or ratify the Constitution.
They are supposed to represent those who elect them. That’s what a representative Republic is. They aren’t doing so. You can argue until the cows come home but they are not representing their electorate. They are not elected to rule over us.