Our long, lost contributor Jack Murphy forwarded us this interesting piece from the Detroit News. Jack is our official “Heartland of America” correspondent. Democratic presidential candidates Barack Obama, John Edwards, Joe Biden and Bill Richardson are withdrawing from Michigan’s Jan. 15 primary ballot, dealing a blow to this state’s hopes of having Michigan’s issues heard in both sides of the 2008 race.

Obama, Edwards and Richardson asked the Michigan Secretary of State to take their names off the ballot, and Biden’s campaign said today he would do the same. They are pulling out because Michigan, like Florida, has violated national Democratic Party rules by moving up its primary date in a challenge to the traditional monopoly on early voting held by Iowa and New Hampshire.

New York Sen. Hillary Rodham Clinton, who has consistently held a comfortable lead among Democrats in Michigan polls, will stay on the state ballot, aides said.

“It’s unnecessary” to remove her name from the ballot, spokesman Mo Elleithee said, because she has already signed a pledge not to campaign in Michigan or other states violating the national party’s scheduling rules.

It was unclear whether any other candidates would file similar requests by today’s 4 p.m. deadline. It’s unclear what happens next — whether the primary will go on as scheduled, or if Democrats will knuckle under to party rules by calling a party caucus Feb. 5 or later. Primaries and caucuses are used to decide what candidate will win a state’s national convention delegates.

Read it here: Clinton stays, four Dems quit Michigan