WASHINGTON - Republican U.S. Rep. John Kline swept into Congress a decade ago when political redistricting helped swing the electorate in the southern Twin Cities suburbs in his favor.

Ten years later, Democrat Mike Obermueller is hoping he'll be able to pull off the same feat: Take advantage of a reshaped congressional district to unseat an entrenched incumbent.

In Kline, Obermueller faces an established politician who has amassed influence and a fundraising stockpile.

A retired Marine, the 65-year-old Kline leads the influential House Committee on Education and the Workforce, which oversees issues ranging from early childhood education to retirement security.

In each of his previous re-election campaigns, Kline has captured a larger percentage of the vote in the Second Congressional District. After winning his last race by 26 points, he has raised more than $2 million in his bid to secure a sixth term.

To do that, he'll have to defeat Obermueller, a 39-year-old attorney and former state representative who state and national Democrats have rallied behind.

"We are confident in the strong grass-roots campaign Mike has built," said Haley Morris of the Democratic Congressional Campaign Committee, which works to elect Democrats to the U.S. House.

Their enthusiasm is fueled by new boundaries. Once-a-decade redistricting earlier this year stripped the district of reliably Republican territory in Carver County while adding Democratic-leaning areas in northern Dakota County and Rice County.

"It's a significant shift," said Carleton College political science Prof. Richard Keiser, who lives in the Second District.

"But the significance is beyond the numbers," Keiser said. "There's increased aspirations for Democrats."

In a district now almost evenly split in its support of the two parties, state Republicans are slightly concerned.

"There are different dynamics at play," said Mark Westpfahl, chairman of the Second District Republican Party.

Keiser said some candidates in such circumstances would drift toward the middle to appease new constituents; the National Journal ranked Kline as the 60th most conservative member of the U.S. House and the most conservative in Minnesota.

But Kline said he intends to run on his record that includes securing promised paid time off for the Minnesota National Guard and efforts to control spending, including his refusal to pursue federal earmarks for his district.

Obermueller is running as a moderate Democrat, focused on protecting Medicare, reining in out-of-control federal spending and repealing the No Child Left Behind Act, a national reform law that some Minnesota educators have heavily criticized. "I want solutions for everyone, not just a political party," Obermueller said.

He's already a familiar face in the district, having represented Eagan in the state House for two years, where he served in the seat once held by former Republican Gov. Tim Pawlenty.

Obermueller has joined other Democratic congressional candidates in criticizing Republicans such as Kline, who support vice presidential candidate Paul Ryan's budget. That spending plan would overhaul Medicare for those 55 and younger by offering vouchers to buy private insurance.

Kline said Medicare is on "an unsustainable path" and "will completely collapse" without change and criticized Obermueller as a "tax-and-spend guy," saying Obermueller supported at least one bill that called for tax hikes.

Obermueller lost his state House seat after one term but said he vigorously fought several of his party's proposals to raise taxes.

With the reshaped district, Westpfahl said Obermueller may cut into Kline's margin of victory, but said he ultimately expects Kline to win.

Even if that happens, Obermueller says he's not going away. He has vowed to run for Congress in 2014.

The approach is similar to one used by Kline at the dawn of his congressional career. It took Kline three runs to secure his seat, after twice losing to an incumbent.

"It's going to give our organization more time," said Susan Moravec, chairwoman of the Second Congressional District DFL. "Mike is in it for the long haul."

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