Senators soon discovered that they could vote however they liked and still serve their entire term. And so they did.
As for fundraising, state legislators are just as beholden as the US House.
If what you want is for Senators to have to vote as instructed by a bunch of other politicians, you’d have to give the legislatures the ability to remove them at at will. I don’t like that idea a whole bunch. I don’t see how that makes anything better. I don’t see how state legislators are special creatures who favor liberty and hate federal power, I think that’s naive. The RINO ones are scum and the dem ones are pond scum, just like House members, just like Senators, just like local politicians.
-PJ