A major union this week waded into the grudge match brewing in Michigan's seventh district between Rep. Mark Schauer (D) and his 2008 foe, Tim Walberg.

The freshman Democrat took the seat from Walberg last cycle after the Republican had held it for a single term. Walberg is now running to get it back, but Schauer's labor allies are closing ranks around him.

The American Federation of State County and Municipal Employees spent $750,000 on a TV ad called "Burned Dignity" that went up on Monday in the Grand Rapids-Kalamazoo-Battle Creek media markets.

 The ad notes that Walberg skipped the vote on the auto industry bailout but "sided with big oil and hedge funds — gave them tax loopholes."

"Haven't we been burned badly enough?," the announcer says in the spot.

In 2008, Schauer beat Walberg by about 7,500 votes.