Bump for Southern genius that preserved states rights, and the federal representation of the states interests.
Present-day senators engage in a much more dangerous bribery of their electors.
...and the fact that a senator could be elected years before service.
Congress has always had the power to revise or impose the time and manner in which its members are chosen. If they wanted to prohibit members from being chosen years before, they could have easily done that without going through the trouble of passing an amendment. And in fact, the 17th amendment didn't even prohibit that from happening. The states could still determine the times of election anyway, until Congress intervened, as before.