Before 1913, State's legislatures would elect their US Senators. Since 1913, Senators are directly elected but to longer terms than their peers in the House, as a way to make them less beholden to the whims of the zeitgeist and more stable in their consideration of "what serves the state" in that they do not face elections immediately and the results of their work are meant to be evaluated over a longer period. -- this is the intent, reality may bear out differently