Whomever could he mean? Actually, Sen. Bill Cassidy thinks that cognition tests might apply at least as much to the leadership of the legislative branch as it does to the executive. As a physician, Cassidy warns Axios’ Mike Allen that cognition can decline rapidly as people age into their eighties … and then tells him to look around Washington:

Cassidy, a gastroenterologist, told me during our wide-ranging interview in Chalmette, La., that in your 80s, you begin a “rapid decline.”

Noting he wasn’t talking about specific people, Cassidy said: “It’s usually noticeable. So anybody in a position of responsibility who may potentially be on that slope, that is of concern. And I’m saying this as a doctor.”

“I’m told that there have been senators in the past who, at the end of their Senate terms were senile,” Cassidy added. “I’m told that was true of senators of both parties.”

Cassidy said it’d be reasonable for Supreme Court justices, members of Congress, and executive branch leaders to submit to an annual evaluation in which they would have to establish cognitive sharpness.

It’s true that some senators and representatives had been suspected of being at least partly non compos mentis at advanced ages, but those members had largely stopped serving in caucus leadership. The one exception to that was probably Robert Byrd, who for some reason was allowed to serve in the presidential line of succession as president pro tempore starting at age 89 despite his obvious decrepitude. Of course, 81-year-old Patrick Leahy took over that same position this January from 88-year-old Chuck Grassley, but at least those two have given fewer reasons to be concerned about their cognition than Byrd did in 2007.

Cassidy scores some points in noting just how old leadership has become on both ends of Pennsylvania Avenue. The top three House Democrats are now all over eight years of age; both Chuck Schumer and Mitch McConnell are in their seventies. That’s less of an issue regarding cognition than it might be about getting younger members invested into leadership, though. Politically the US should have moved past the boomer generation by now, but we keep electing septuagenarians and octogenarians into leadership.

But of course, Cassidy’s almost certainly referring to Joe Biden with these concerns, not McConnell or Nancy Pelosi, whom Cassidy mentions to make his point more broadly. Biden has given much more reason to worry about his cognition, not the least of which has been the White House’s cocoon around Biden ever since his election. It’s been three months since Biden did a sit-down interview with a national-outlet reporter; his last was the disastrous interview with George Stephanopoulos, in which he pledged to leave no Americans behind in Afghanistan while abandoning thousands of them. When Biden does come to the podium, he looks and sounds frail. It’s tough to suss out whether Biden really has significant cognitive decline or whether he’s just his usual incompetent self, but a cognition test would at least quantify his status … which is why he would never take one. Nor would his handlers allow it.

Besides, this is just a fantasy. Cassidy may have a point as a physician, but not as a political analyst. How exactly would cognition tests work in a democracy (or representative republic, for the pedants)? You can’t require them for elections, as it would violate well-considered privacy laws. Even if they were required, it would leave the medical-care system in charge of prequalifying candidates, which is not a tenable solution in a free country. Voters could pressure candidates into taking cognition tests and releasing the results, but that would likely only result in doc-shopping rather than any real transparency on competence. House and Senate caucuses can set their own rules on leadership, but try to imagine Pelosi or McConnell submitting to such a demand, and it’s tough to see how that would get enforced.

If we have House or Senate caucus leaders who exhibit signs of senility, then their caucuses can take action to replace them. If a president becomes non compos mentis, the Cabinet can take action through the 25th Amendment. Those aren’t perfect solutions, but they beat the idea that we should require cognition tests to access public office. The best solution is to quit electing septuagenarians and octogenarians to high public office.