We have another shocker this evening–various outlets are reporting that Colorado Governor Bill Ritter (D) is ending his re-election campaign.

From Political Wire:

A source tells Political Wire that Colorado Gov. Bill Ritter (D) is ending his re-election campaign. A fundraiser scheduled for tonight was canceled and all campaign staff was sent home in the middle of the day.

[Emphasis mine]

And Marc Ambinder tweets:

Another stunner for Dems: CO Gov. Bill Ritter is dropping out of the race.

There has been no official confirmation, but if it’s true it will be a pretty baffling turn of events–Ritter is popular, his fundraising was going well and polling was pretty favorable.

The only motivator I can think of is that some of the polling comparing Ritter to former Rep. Scott McInnis–the probable GOP candidate–showed a very tight race, but a handful of polls taken a significant time before election day doesn’t really warrant dropping out.

Regardless, I’ll follow this as the night wears on…

UPDATE: The Fix confirms and lists some potential replacement Dem candidates:

Democrats are likely to turn to either former state House SpeakerAndrew Romanoff or Denver Mayor John Hickenlooper to replace Ritter. Romanoff is currently challenging appointed Sen. Michael Bennet in a Democratic primary and if he could be convinced to switch races would solve two problems for the party.

UPDATE II: The Hotline also confirms and discusses the likely Dem candidates:

Ritter’s departure could leave Dems scrambling for a candidate just 11 months before Election Day, but the party has strong potential candidates. 3 of the 4 other statewide elected officials are Dems, and Denver Mayor John Hickenlooper (D) has long contemplated running for statewide office.

In ’06, Hickenlooper largely froze the Dem field while he thought about running, leaving Ritter — who had already entered the race — with a dry fundraising field. Hickenlooper would be an instant frontrunner on the Dem side if he chooses to run.

UPDATE III: The Denver Post is reporting that Gov. Ritter will hold a press conference explaining his decision at 11:00 AM tomorrow (1:00 PM here on the east coast).

They also mention Interior Secretary (and former Sen.) Ken Salazar and prominent Rep. Ed Perlmutter as potential Democratic candidates.