US Senate gets older and older

I heard the news that Senate John McCain won his primary and he is more than  80 years old. My impression for John McCain is that there is no war he does not like.

Then I checked around and found the average age for US senators is becoming older and older. The trend starts from 1979. What is happening in the society?

US senate gets older and older

For the current US senate age, please see

Some statistics:

There are eight senators who are over 80 years old, six from Republican and two from Democrat. Even they are old, either Republic or Democratic parties seems worried at all about this aging issue. Since the governors from those states probably belongs to the same party as the senators. If the senate position vacant suddenly, those governors can assign a new senator from the same party.

There are 5% senators served more than 30 years. There are 20% senators who have served more that 18 years, another 10% severs more than 12 years. That is 30% serves more than three terms.

There are 13% senators who just served over a year and half.

US senators more than 18 years

Two senators from Maryland are:

7 Barbara Mikulski Maryland July 20, 1936 January 3, 1987 50 years, 167 days 29 years, 241 days 80 years, 42 days Democratic
19 Ben Cardin Maryland October 5, 1943 January 3, 2007 63 years, 90 days 9 years, 241 days 72 years, 331 days Democratic