Updated at 5:00 p.m.

Democrat Rep. Tim Walz snagged the endorsement of former Republican Sen. Dave Durenberger on Monday, a cross-party boost aimed at winning over moderate voters in southern Minnesota.

The endorsement follows news last week that national Republicans had elevated Walz’s challenger, state rep. Randy Demmer, to their “Young Guns” list – making MN-1 their top target in Minnesota.

Durenberger, who is now a Senior Health Policy Fellow at the University of St. Thomas, helped moderate Rep. Tim Walz’s health care town halls in late 2009.

He said in an interview that he was impressed at the time with Walz's efforts to "bring everybody together." 

“I’m not going around looking for middle-of-the-road Democrats to support," Durenberger said. "He’s a unique human being.”

As for Demmer, Durenberger remarked that he could not support someone who wants to repeal the recently passed health care bill. 

Though he still identifies as a Republican, the Star Tribune reported in 2009 that Durenberger voted for Obama. Durenberger also supported Independence Party candidate Tom Horner, a former staffer, earlier this year.

In a statement, Demmer's campaign accused Walz of being a reliable vote for "an extreme liberal agenda." 

“No endorsement that Tim Walz receives will change the fact that what he likes to call 'working across party lines' actually means unwavering support for every item on the Obama/Pelosi wishlist," said Demmer campaign manager Jason Flohrs.