AP:

New Mexico Gov. Bill Richardson ended his campaign for the presidency Wednesday after twin fourth-place finishes that showed his impressive credentials could not compete with his rivals' star power.

Richardson planned to announce the decision Thursday, according to two people close to the governor with knowledge of the decision. They spoke on a condition of anonymity in advance of the governor's announcement.

The Richardson campaign would not comment on the governor's decision, reached after a meeting with his top advisers Wednesday in New Mexico.

Richardson was the only candidate who promised "no residual forces" in Iraq. The popularity of that message with Democratic voters, promoted by bloggers, put a lot of pressure on the other candidates to abandon more hawkish positions.

He made an important contribution to the 2008 race.

*Update: Sorry, Kucinich fans. Dennis promised no residual forces, too. My bad.

Update II: Or not...MSNBC says the Richardson campaign is denying it.