Here's one I never saw coming:

Sen. Byron Dorgan, a North Dakota Democrat in his third term, announced late this afternoon he will not seek re-election this year:

I have been serving as an elected official in our state for many years. Beginning at age 26, I served ten years as State Tax Commissioner followed by thirty years in the U.S. Congress by the end of 2010. It has been a long and wonderful career made possible by the people of North Dakota. And I am forever grateful to them for the opportunity.

Although I still have a passion for public service and enjoy my work in the Senate, I have other interests and I have other things I would like to pursue outside of public life. I have written two books and have an invitation from a publisher to write two more books. I would like to do some teaching and would also like to work on energy policy in the private sector.

So, over this holiday season, I have come to the conclusion, with the support of my family, that I will not be seeking another term in the U.S. Senate in 2010. It is a hard decision to make after thirty years in the Congress, but I believe it is the right time for me to pursue these other interests.

Dorgan's retirement is a major opportunity for Republicans. North Dakota reliably votes GOP for president — John McCain took 53 percent of the vote in 2008 — but a Republican hasn't won a Senate seat there since 1980. Gov. John Hoeven, a popular Republican, has often been mentioned as a potential Senate candidate but he has never taken the plunge. Perhaps with Dorgan out of the race, he might run.

The Democrat most likely to get in the race is Earl Pomeroy, the state's at-large congressman. In 2008, Pomeroy took 62 percent of the vote in winning a ninth term. (In winning re-election that same year, Gov. Hoeven got 74 percent.)

Still, as Politico's Josh Kraushaar writes, North Dakota "becomes a prime pickup opportunity for Senate Republicans." Add that to the fact that President Obama's "domestic agenda hasn't been viewed favorably" in the state.

Dorgan is the third Democratic senator to retire this year, but unlike the other two — appointees Ted Kaufman in Delaware and Roland Burris in Illinois — he has a strong track record of winning elections. Six Republicans are leaving: appointee George LeMieux in Florida, Sam Brownback in Kansas, Jim Bunning in Kentucky, Kit Bond in Missouri, Judd Gregg in New Hampshire and George Voinovich in Ohio.

Tags: On The Ballot