A 79 year-old freshman senator would be … unusual

Maine Gov. Janet Mills (D) has announced her intention to run for Senate against the state’s well-known — ahem — incumbent, Susan Collins. When the next Senate term begins in January 2027, Collins will be 74 years old, well past the typical retirement age in the United States. But Mills will be 79 — well, well past the typical age at which one assumes a new, stressful job.

It used to be relatively rare for anyone as old as Mills would be to serve in the Senate at all, much less as a freshman. Until the 114th Congress (2015–2016), no more than seven senators served in a single congress who would have turned 79 by the end of the congress’s second year. Since the 114th Congress, though, there have been at least eight in each congress. The current, 119th Congress, has 11 senators who will be 79 or older by the end of next year.

You can see on the chart below how the age of sitting senators has slid upward — as, of course, has the age of the American public.

There are some senators who stand out on the chart above. The series of dots that extends all the way to the 100 mark, for example, indicates Strom Thurmond, who served as a senator for nearly 1 in 5 years that the U.S. has been in existence.

Often, freshmen senators who were in their 70s and 80s were appointed to fill vacancies. The oldest new senator (according to my analysis of VoteView data), was Andrew Jackson Houston, appointed at age 86 to fill a vacancy. He started in April 1941. He died in June 1941.

By my count, there are seven freshman senators in U.S. history who would have been 79 or older by the end of the congress in which they first served. All but one, Isaac Stephenson, was appointed. Stephenson was elected, assuming office in 1907 at the age of 77 — more than a year younger than Mills would be.

Until the 1860s, almost or more than half of senators were under the age of 50. That hasn’t been the case since the congress that ended in 1868. Over the past five congresses, an average of just under 10 percent of senators have been under the age of 50. In the current congress, more than 10 percent will be 79 or older by the end of next year.

When Rep. Jerry Nadler (D-N.Y.) announced his intent to retire back in September, I suggested that the Democratic Party was slowly beginning to recognize its generational problem. It will be in part up to primary voters in Maine — given a choice between Mills and a 40-something challenger — to determine the extent to which the party’s base agrees that there’s a problem at all.

Given that Maine’s residents are the oldest of any state, they may not.

Photo: Ronald Reagan and Strom Thurmond in 1987. (National Archives)