The Washington Post and the Associated Press, citing Democratic sources, say that Colorado Gov. Bill Ritter will not seek a second term this year.
While thought to be favored for re-election over former Rep. Scott McInnis (R), Ritter has made some enemies in the party, notably his decision to pick Michael Bennet to fill the Senate seat vacated by now Interior Secretary Ken Salazar. Former state House Speaker Andrew Romanoff, who thought he was going to get the Senate appointment, never hid his anger over the rejection. At first he considered challenging Ritter for the governorship, then decided to run against Bennet. Ritter's retirement may mean that Romanoff will once again focus on the gubernatorial race.
Another potential Democratic candidate is the popular mayor of Denver, John Hickenlooper.
A majority of the governorships at stake this year will be open, but mostly due to term limits. Of all the incumbents leaving office this year, only five are voluntarily retiring, in addition to Ritter: Jody Rell (R-CT), Mark Parkinson (D-KS), Tim Pawlenty (R-MN), Jim Douglas (R-VT), Jim Doyle (D-WI). Also, Charlie Crist (R-FL) is running for the Senate.
Here is a complete list of the governors who are stepping down this year:
Alabama -- Bob Riley (R) (term limited)
California -- Arnold Schwarzenegger (R) (term limited)
Colorado -- Bill Ritter (D) (retiring)
Connecticut -- Jody Rell (R) (retiring)
Florida -- Charlie Crist (R) (running for Senate)
Georgia -- Sonny Perdue (R) (term limited)
Hawaii -- Linda Lingle (R) (term limited)
Kansas -- Mark Parkinson (D) (retiring)
Maine -- John Baldacci (D) (term limited)
Michigan -- Jennifer Granholm (D) (term limited)
Minnesota -- Tim Pawlenty (R) (retiring)
New Mexico -- Bill Richardson (D) (term limited)
Oklahoma -- Brad Henry (D) (term limited)
Oregon -- Ted Kulongoski (D) (term limited)
Pennsylvania -- Ed Rendell (D) (term limited)
Rhode Island -- Don Carcieri (R) (term limited)
South Carolina -- Mark Sanford (R) (term limited)
South Dakota -- Mike Rounds (R) (term limited)
Tennessee -- Phil Bredesen (D) (term limited)
Vermont -- Jim Douglas (R) (retiring)
Wisconsin -- Jim Doyle (D) (retiring)
Wyoming -- Dave Freudenthal (D) (term limited)