Senator Dianne Feinstein's visible decline in her final years in office. Senator Lindsey Graham's sudden death. Senator Mitch McConnell's own recent hospitalization, and his halting explanation of it afterward. Three senators, three separate incidents, no obvious connection between them, except that the saga of these three senators is really one story about the problem of not knowing when to step down. That framing asks the right question of individual leaders. But it assumes the problem is a matter of personal judgment, each senator, in his or her own time, finding the wisdom to recognize the moment has passed. I think that gets the American version of this problem backwards. Congress's age problem is not a string of individual judgment calls. It is a structural feature of the Constitution itself, and it is quietly reshaping who gets represented in American government.

The Constitution sets a floor for federal office and no ceiling. A representative must be at least twenty-five. A senator must be at least thirty. A president must be at least thirty-five. Nothing in the document says how old is too old. Combine that asymmetry with the enormous advantages of incumbency, better name recognition, fundraising networks, committee seniority, and the result is predictable: a Congress that can start young but can never age out. It can only age up. The 119th Congress is now the third oldest in American history, with an average member age of nearly fifty-nine and a Senate averaging in the mid-sixties. This is not a temporary blip. It is the natural output of a system with a gate on one end and no gate on the other.