A lot of the democrats longevity can be explained by certain areas (mostly urban cores) having been democratic for a lot longer than any comparably large area has been republican (so more opportunity for a super old incumbent). Also democrats had and have a lot more super safe seats, so they would be expected to win them all the time, increasing an incumbents tenure.
That was true up until 20 years ago, but not so much anymore. Also, there used to be a lot of super-old Dixiecrats.
Well yes, but the republicans who won seats in 1994 still won't be old enough to show up on the lists.
