"Top Democrats withdraw from Michigan primary" (Updated)

UPDATE: The Detroit Free Press says "Clinton will keep name on Michigan ballot."

AP:

Barack Obama, John Edwards and Bill Richardson have withdrawn from Michigan's Jan. 15 Democratic presidential primary.

The three filed paperwork Tuesday, the deadline to withdraw from the ballot, said Kelly Chesney, spokeswoman for the Michigan Secretary of State's office.

All of the Democratic candidates already have agreed not to campaign in Michigan because it broke Democratic National Committee rules when it moved its primary ahead of Feb. 5. The decision by Obama, Edwards and Richardson undercuts the validity of the contest.

Other Democratic candidates had until the end of the day to decide if they'll stay on the ballot.

Party rules say states cannot hold their 2008 primary contests before Feb. 5, except for Iowa on Jan. 14, Nevada on Jan. 19, New Hampshire on Jan. 22 and South Carolina on Jan. 29.

The calendar was designed to preserve the traditional role that Iowa and New Hampshire have played in selecting the nominee, while adding two states with more racial and geographic diversity to influential early slots.

As punishment, the DNC has vowed to strip Michigan and Florida, which scheduled its contest on Jan. 29, of their delegates.

Howie P.S.: Markos says this is "Ridiculous" and he links to Ben Smith's roundup of the story.