If the 17th amendment was repealed, the Senate would be solidly Republican right now. It used to be that Governors appointed Senators to sit in DC to represent the interest of the state. Now they’re “popularly elected” which simply makes it easier to defraud the federal elections.
Actually, it was the state legislatures. The federal senator was originally the envoy of the legislature of his state, with the job of protecting the power of his state's government against federal usurpation.