Three Congressional Incumbents Lose Primaries

Somewhere there's a political stat freak who can tell us when the last time three incumbent members of Congress lost primaries on the same day.
Ned Lamont's victory over Joe Lieberman got the headlines, but two other incumbents lost their primaries: In Georgia, Cynthia McKinney lost to Hank Johnson in a primary runoff. And in Michigan, Republican Joe Schwartz lost to Tim Walberg, who attacked Schwartz for his moderate social views.
As the Washington Post reports, Lieberman was hardly chastened by his loss:

"I'm disappointed not just because I lost but because the old politics of partisan polarization won today. For the sake of our state, our country and my party, I cannot and will not let that result stand."

The New York Times reports that Republicans are eager to portray the Connecticut result as a sharp lurch to the left:

Ken Mehlman, the Republican National Committee chairman, is planning to give a speech in Columbus, Ohio this morning in which he will use Mr. Lamont’s victory to portray Democrats as a party weak on national defense, and his affiliation with blogs to present the Democrats as captive to the extreme wing of the party, Republican aides said.

But is Connecticut a hotbed of wild-eyed radicalism? Not to Ned Lamont:

"They call Connecticut the land of steady habits," he said to supporters. "Tonight we voted for a big change."

This Times editorial disputes the notion that this was an election result driven by radicalism:

The rebellion against Mr. Lieberman was actually an uprising by that rare phenomenon, irate moderates. They are the voters who have been unnerved over the last few years as the country has seemed to be galloping in a deeply unmoderate direction.

In Georgia, the result was a repudiation of McKinney's argumentative temperament and embarrasment over her altercation with a Capitol police officer. The Atlanta Journal-Constitution reports that challenger Hank Johnson made McKinney's conduct the issue in the campaign:

Johnson constantly reminded voters that she had been more of an embarassment than a benefit to the affluent and diverse district, more polarizing than productive at home and in Washington.

In Michigan, challenger Tim Walberg ran on a conservative social agenda, defeating incumbent Joe Schwartz despite support from President Bush and John McCain. The Detroit Free Press reports that Walberg's was the first successful challenge in 14 years:

First-term U.S. Rep. Joe Schwarz failed in his bid for re-election Tuesday, losing to former state Rep. Tim Walberg in the Republican primary and becoming the first Michigan congressman since 1992 ousted by a challenger who was not already in Congress.

The Times reports that Schwartz lamented his loss as moving the GOP further to the right:

He said the primary was ''probably a victory for right to life, anti-abortion, anti-embryonic stem cell groups but it's a net loss for the Republican party because it just pushes the party farther to the right.''

Can you spot the trend? In Connecticut, a Democratic defender of Bush's war in Iraq loses and vows to run as an independent. In Georgia, Democrats dump a polarizing, volatile figure for someone less, shall we say, invigorating. And in rural Michigan, Republicans replace a moderate with a staunch social conservative.
Economists would call this a spike in volatility.
Perhaps Bob Dylan described it best, "You know there's something happening, but you don't know what it is..."