With the Senate set to take up the Defense authorization bill this week, Sen. Norm Coleman (Minn.) will become the latest Republican to feel the sting from a liberal group that has been targeting Members of Congress — most of them Republican — for continuing to support the Iraq War.

Americans United for Change is launching a 10-day TV ad buy today, urging Minnesotans to express their displeasure with Coleman’s Iraq stance. The group is spending “in the low but significant six figures” to air the ads in the Minneapolis market, which reaches about 80 percent of the voters in the state, according to Americans United Executive Director Brad Woodhouse.

Coleman, who was elected narrowly in 2002, is a major Democratic target this election cycle and could be especially vulnerable in a Democratic-leaning state where the war is unpopular. Comedian Al Franken (D) and wealthy attorney Mike Ciresi (D) are competing for the right to face Coleman in the general election.

The 30-second ad, which was produced by the Democratic firm GMMB, opens with footage of President Bush in front of a “Mission Accomplished” banner four years ago and continues with chaotic scenes from the war.

“After four years with no end in sight, thousands of Americans wounded, Iraq in civil war and over 3,500 Americans dead, Norm Coleman is still standing with President Bush in Iraq, voting time and again against bringing our troops home,” a narrator intones. “Tell Norm Coleman, after four years, it’s time to end the war.”

Woodhouse said the group felt compelled to target Coleman because the first-term Senator was dismissive recently when Sen. Dick Lugar (R-Ind.) expressed his reservations about the country’s course in Iraq. Two other veteran Republican Senators, George Voinovich (Ohio) and Pete Domenici (N.M.), in the past few days have joined Lugar’s call for a new direction in Iraq.

“Norm Coleman continuing to support the president’s policy in Iraq is completely out of step with the people of Minnesota,” Woodhouse said. “This ad is putting him on notice that time has run out.”

Coleman’s office did not respond to a request for comment by press time Friday.