WASHINGTON – During the 2012 campaign, Democratic U.S. Rep. Tim Walz was a target of national Republicans who saw his conservative-leaning district as prime for the picking.

The former high schoolteacher survived the test, winning re-election by 16 points.

Now House Democratic leaders have a new assignment for Walz: Take the helm of the Democratic Congressional Campaign Committee's Frontline Program, mentoring Demo­crats in competitive districts from California to Connecticut in preparation for 2014's midterm elections.

Being appointed the Frontline Program's chairman could signal that Walz is a politician to watch. The previous three program leaders, including Democratic National Committee Chairwoman Debbie Wasserman Schultz, have ascended the party ranks, taking on more prominent roles.

But President Obama's plan to push for Democratic control of the House in order to advance his domestic agenda could complicate an already tall task for Walz.

Polls show that Obama's positions on immigration, gun control and same-sex marriage are gaining support nationwide. But the battle for House control will come in several dozen moderate- to conservative-leaning districts, where Obama's agenda is more problematic.

"Tim is a former Frontline member, so he understands what these members need to do to compete and win independent votes," said U.S. Rep. Steve Israel of New York, chairman of the Democratic Congressional Campaign Committee.

In midterm elections since World War II, the president's party has lost an average of 25 House seats. Democrats would need a net gain of 17 seats to win a majority in 2014. To do that, they must first protect the 26 Frontline seats.

"I do understand that the stakes are high," Walz said. "We can't lose any of these folks."

From pupil to pacesetter

In 2006, Walz pulled off the kind of victory that Democrats hope to duplicate en masse next year; he unseated a seven-term Republican to win his southern Minnesota seat. Since then, Walz has twice tapped Frontline for help with fundraising and volunteers.

Now he's morphing from pupil to professor, with a specialty in fundraising. During the past three elections, Walz raised more than $2 million on average, a sizable sum for his sprawling, rural district, said University of Minnesota political scientist Kathryn Pearson.

Walz also may end up teaching a lesson just as critical as fundraising: branding. In Congress, Walz has focused on farm and veterans' issues and resisted being portrayed as a dyed-in-the-wool liberal, even as Republicans accuse him of voting like one. According to opencongress.org, a site that tracks congressional voting trends, Walz votes with his party 88 percent of the time. Of the House's 200 Democrats, only 16 vote with the party less often.

For a candidate running in a conservative-leaning district, parting ways with the White House on a few issues could provide a buffer from GOP attacks, said Columbia University political scientist Robert Erikson.

Walz has supported Obama's key initiatives, such as health care reform, but has veered from the party line on several tax votes. He also is a gun owner who is backed by the National Rifle Association.

That has not slowed Republican criticism. "It's clear that Walz is more interested in getting jobs for his fellow liberal politicians in Washington than his hardworking constituents at home," said National Republican Congressional Committee spokeswoman Alleigh Marre.

More hurdles

In their push to recapture the House, Democrats face additional hurdles in history and geography — two subjects Walz once taught.

In 2010, the midpoint of Obama's first term, Democrats ended up with a loss of 63 seats and control of the House.

Clawing back from that could prove tough now that once-a-decade congressional redistricting has helped pack more Democrats and Republicans in safe seats, reducing the number of competitive districts, said Jessica Taylor, a senior analyst with the Rothenberg Political Report.

Of the 50 House races that the nonpartisan newsletter lists as competitive in the 2014 election, about 30 are in districts that lean Republican, including the western Minnesota seat of fiscally conservative Democrat Collin Peterson.

Democrats, including Walz, head into the next election with little margin for error. In the 2010 midterm election, when Republicans gained control of the House, Walz won re-election by only five percentage points. "I'm never too far from the target list," Walz said.

Corey Mitchell is a correspondent in the Star Tribune Washington Bureau. Twitter: @C_C_Mitchell