As Republicans look toward rebuilding their party and inching back to the majority, an accurate diagnosis of what went wrong will be critical to finding the eventual cure. Taking a look at the long list of GOP retirements this year, one thing becomes clear: The Democratic Party has claimed the middle of the political spectrum by running more centrist and conservative candidates.

Twenty-nine members of the current House Republican Conference will not be members of the same conference next year. Most, 23, are retiring from public service, while a handful of others are seeking higher office or have already lost their primary battles. Of those members who are retiring, a significant number include the rapidly dwindling breed of moderates, members who resembled Bob Dole more than Bob Dornan. At the same time, a new breed of Democrats are storming the Capitol, moderates in their own right who more closely hue to Gene Taylor than to Gene McCarthy.

As Republicans are replacing their own moderates, Democrats have thrown open their arms to candidates who might make a liberal from San Francisco blush. According to National Journal's 2007 House vote rankings, fifteen Democrats have liberal scores below, and conservative scores above, the median, while not a single Republican scored above the 50% marker on the liberal side or below it on the conservative side.
The number of more centrist and conservative Democrats is increasing. Of the forty-one freshmen elected in 2006, including three who had served in Congress previously, fifteen spent their first year earning liberal scores of 55% or less. In the three special elections Democrats won earlier this year, two of those winners -- Reps. Don Cazayoux of Louisiana and Travis Childers of Mississippi -- are likely to compile similarly conservative voting records.

They join the likes of Taylor, also of Mississippi, Jim Marshall and John Barrow of Georgia, and John Tanner and Lincoln Davis of Tennessee. The 2006 freshman class also added a boatload of new conservative Democrats, including Reps. Heath Shuler, of North Carolina, Chris Carney of Pennsylvania and Joe Donnelly of Indiana.

Those new members of Nancy Pelosi's party were recruited less for their ability to compliment any liberal policy aim and more for their ability to win the districts. That's how the party plans to win seats this year, too, DCCC executive director Brian Wolff told Real Clear Politics. "These are going to be the more fiscally responsible" Democrats, he said. "We're not talking about a lot of progressive Democrats that are running."

Those more moderate members have already created a new and increasingly powerful coalition in Congress. Thirteen freshmen are members of the Blue Dog coalition of fiscally conservative Democrats, which this session has earned a more prominent seat at the leadership table.

While Democrats are building their ranks of moderates, Republicans are losing their centrists. Of the twenty nine members who will not be back next year, at least twelve are considered moderates. Members like Tom Davis of Virginia, Jim Saxton of New Jersey and Illinois' Ray LaHood will step aside at the end of their terms, further pushing this breed of Republican moderate down the path to extinction.

As conservatives have taken over the Republican Party, moderates have increasingly been the victims. The Club for Growth, which has made a crusade of ousting what it sees as members who are not conservative enough, helped Rep. Tim Walberg knock off Rep. Joe Schwarz in Michigan in 2006 and this year backed State Senator Andy Harris, who beat Rep. Wayne Gilchrest in the Maryland Republican primary. Gilchrest and Schwarz were two of the most centrist Republicans in the conference. The Club for Growth also backed conservative Rep. Steve Pearce over moderate Rep. Heather Wilson in the fight for New Mexico's Senate seat.

Democrats are seeking new targets ahead of November, and it should come as little surprise that the remaining moderate Republicans are some of their top targets. In a major television advertising reservation last week, the DCCC reserved millions on behalf of Democratic candidates challenging moderate Reps. Christopher Shays of Connecticut, Nevada's Jon Porter and Michigan's Joe Knollenberg.

Moderate members tend to represent moderate districts, so seats being vacated by Reps. Jim Ramstad, in Minnesota, Vito Fossella, in New York, Deborah Pryce, in Ohio, and Wilson and Davis are also on Democrats' top target list. In those seats, where independent voters reign, Republicans face more evidence that they have lost the center. Independent voters told pollsters at Pew Research Center they favored the generic Democratic congressional candidate by a 44%-34% margin.

There remains a great American middle that will determine who owns the majority in Congress. Republicans, in their search for their conservative roots, have abandoned that middle to Democrats like Childers and Cazayoux. Until they find a way to replace their extreme right with their more moderate middle as the face of the party and as the winners of GOP primaries, Democrats will own the center, and with it, the gavels in both chambers of Congress.
Reid Wilson is an associate editor and writer for RealClearPolitics. He can be reached at reid@realclearpolitics.com