The senator's office has announced that she will not seek reelection in 2024. Some Democrats outside the Senate have publicly called on her to resign now so that California's Democratic governor can appoint a successor and the Judiciary Committee can have a new member.

But Feinstein has refused to step down or even to discuss it, at least so far. That means that for the remainder of the 118th Congress, her ability to attend and vote will be a matter of intense concern for her party.

It also raises questions about the institution's ability to deal with its internal issues of absence due to aging or disability.

Far from new, these issues have been part of the Senate's peculiar sense of itself and the prerogatives of its members throughout the institution's history.

South Carolina's legendary Strom Thurmond served in the Senate until shortly after his 100th birthday, performing his duties as the Senate president pro tempore. Also holding that position to the end was Robert C. Byrd of West Virginia, who died in 2010 at age 92 after 51 years in the Senate (still the record).