He’s the only Democrat left in Arkansas’ U.S. congressional delegation, but Rep. Mike Ross won’t seek reelection in 2012. The Wall Street Journal reports:

“While I have worked hard to bring folks to the middle to craft commonsense solutions to the many problems that confront our nation,” Mr. Ross said in a statement, “Washington is mired in gridlock, gamesmanship and constant partisan bickering.”

Mr. Ross represents a district that supported Sen. John McCain (R., Ariz.) over President Barack Obama in the 2008 presidential election, 58% to 39%. He is the only Democrat in Arkansas’s four-member House delegation.

According to the non-partisan Cook Political Report, Mr. Ross’s district is likely to lean more Republican after a redistricting plan goes into effect. The report said the newly created district would likely be a “headache for Democrats” if Mr. Ross didn’t run.

The ranks of the Blue Dogs have already dwindled significantly, thanks to the 2010 midterm election, in which a number of moderate incumbents met defeat. According to the WSJ, “mod Dems” in the House shrank from 51 in the 110th Congress to just 25 in the 111th.

Some (Ross, included, it appears) might say that that reflects the increasing partisanship that characterizes politics — and that’s true. But it is also a reflection of just what a watershed the passage of Obamacare really was. Some Blue Dog Democrats might have fought for a less expensive bill, but, in the end, the president achieved the signature legislation he so acutely angled for. And that fact made conservatives in both parties realize they’d better vote for the most conservative candidate, period. After all, when all is said and done, a Congressional representative with a “D” behind his name answers to the pressure of Democratic leadership in Congress — and that leadership cannot, on any level, be characterized as “conservative.”

From a certain nostalgic, idealistic perspective, the shrinking numbers of Blue Dogs is truly lamentable. How nice it would be if our senators and representatives still met over friendly meals and met in the middle on controversial issues! But from a practical, forward-thinking perspective, the increasing polarization at least makes the choice between big-government and small-government advocates clearer (especially when Republicans actually hold the conservative line — but more on that in another post!).

It’s certainly encouraging to see the congressional delegation of a conservative state like Arkansas actually reflect the conservatism of the state. Ross’ exit opens the door for a complete transformation of that delegation.