With the retirement of Senator Max Baucus (D-MT), Chris Wilson writes at Yahoo News about the departures of veteran senators in recent years:
The flight of the old-timers is neatly captured by a pair of simple statistics: When the 110th Congress convened on Jan. 3, 2007,the 100 senators had a combined 1,328 years of experience in theUnited States Senate. When the 113th Congress convened last January, that figure had fallen to 1,040.
Baucus, D-Mont., is the sixth veteran Democratic senator to head for the exits rather than run for reelection next year. Even if every other current senator stays put, the 114th session of the Senate will have fewer than 1,000 combined years of incumbency for the first time since 1985.
The peak Senate tenure in 2007 is a particularly impressive statistic given that 12 of those 100 senators had just been elected to the chamber in the previous election. If you switch to the House view, you see a much more responsive graph, with huge dips after Watergate and during President Bill Clinton’s first term. That makes sense; a senator has a two-in-three chance of dodging a politically toxic year for congress, like 2006 or 2010,while House members have to face voters every two years.
If you study the graph of Senate tenure carefully, you can also see a significant dip in the early twentieth century as states moved to direct election of senators—a policy enshrined in the 17th amendment, adopted in 1913.