This Dem talking point has come up before.
Historical Perspective:
The Founding Fathers provided that the Senators be chosen by State Legislatures rather than by the direct vote of the common people. By that provision, the Founding Fathers ensured that Senators would be chosen from among the aristocratic class rather than plucked out of the backwoods.
That was the "cooling effect" originally envisioned by the Founding Fathers: Aristocrats "cooling" the passions of the common man.
All that went by the wayside when the 17th Amendment to the US Constitution provided for the direct election of Senators in 1913.
I think the Pubbies ought to use a baseball analogy. It's top of the nineth, bases loaded and the Republicans have their power batter at bat. Now the Rats are refusing to pitch ...