I don’t think I’ve said anything about this one since Tommy Thompson (71) won the GOP primary in Wisconsin. It’s time for an update. Recall the basics here: Congress has been getting older and older for some time now, although there was a bit of a reversal in the current Congress from record highs. So how are things looking for the next Congress?

It looks as if the next Senate will be almost exactly as old as the current Senate.

I’m going to look at incumbent compared with most likely replacement, and I’m going to use Nate Silver’s current estimates. Why? Because it’s easy! But note that his program is hardly infallible; it’s just a quick way to see what’s going on. Ages are for January 2013.

So: leaving the Senate are Lieberman (70), Akaka (88), Bingaman (69), Conrad (64), Webb (66), Kohl (77), Snowe (65), Kyl (70), Ben Nelson (71), Hutchison (69), and Lugar (80). Also losing currently are Tester (56) and Brown (53).

Taking their places? Murphy (38), Hirono (65), Heinrich (41), Berg (53), Kaine (54), Baldwin (50), King (68), Flake (50), Fischer (61), Cruz (42), Donnelly (57), Rehberg (56), and Warren (63).

The outgoing Senators, including the two running, have an average age of 69.1; the incoming favorites average just 53.7. Wait a second…the new group is exactly 200 net years younger than the old group! How does that happen? For what it’s worth…the only other turnover was Dean Heller, who is two years younger than John Ensign. So given that everyone else gets two years older (including the retiring or defeated Senators)…the next Senate would be almost identical in age in January 2013 to what the old Senate was in January 2011.

What are the key races? I count five contests thought to be reasonably close now and with an age gap over more than six years (younger candidate first):

There’s a 21 year gap between Baldwin (84% likely to win via 538) and Thompson.
A 26 year gap between Murphy (74%) and McMahon.
A 10 year gap between Brown and Warren (82%).
A 13 year gap between Flake (62%) and Carmona.
A 9 year gap between Heller (71%) and Berkeley.

As much as I don’t think that Tommy Thompson is a very strong candidate, I think that 84% for Tammy Baldwin is silly-high. But at any rate, it’s Wisconsin and Connecticut that are going to determine how old the next Senate are, basically, at this point. By the way, overall younger candidates are doing quite well in the contested races. Whether that’s an omen for the presidential election or not, I couldn’t say.

[Cross-posted at A plain blog about politics]

Jonathan Bernstein

Jonathan Bernstein is a political scientist who writes about American politics, especially the presidency, Congress, parties, and elections.