U.S. Rep Michele Bachmann, R-Minn., in a file photo. She won her re-election bid Tuesday, Nov. 6, 2012 against challenger Jim Graves. AP Photo/Chris O'Meara

U.S. Rep. Michele Bachmann won a close race Tuesday over DFL candidate Jim Graves in Minnesota's 6th Congressional District.

With more than 97 percent of precincts reporting, Bachmann was leading by 2,600 votes out of more than 300,000.

"Humbled and honored to be reelected to Congress. Grateful to steadfast supporters and amazing volunteers," Bachmann tweeted.

Graves led in St. Cloud and split the vote in suburban Anoka County. Bachmann ran strong in exurban Wright, Sherburne and Carver counties.

The tightness of the contest appeared to catch both campaigns off guard. Bachmann had a massive $11.1 million fundraising advantage and polls showed her with a lead.

The district's boundaries were redrawn, making it the most conservative district in the state, but for the first time, Bachmann was not running with a third party candidate in the race. Bachmann's presidential bid, although unsuccessful, elevated her political profile.

The district includes the St. Cloud area and reaches into the exurban and suburban area north of the Twin Cities all the way to the St. Croix River on the Wisconsin border.

Sixth District DFL challenger Jim Graves greets supporters at Le St. Germain Hotel in downtown St. Cloud, Minn., on Tuesday, November 6, 2012, during his election party. Graves is challenging Republican incumbent Michele Bachmann. Tom Baker for MPR

The redrawn boundaries appeared to help Bachmann, particularly in Carver County west of Minneapolis, which was added to the district this election.

Graves, a political newcomer, struggled to introduce himself to voters. His campaign hoped his debate performances would boost support, but Graves downplayed expectations as the polls closed.

"I would say we're an underdog, no question," he said as the vote-counting began.

The race was markedly different than the 2010 election, in which Bachmann defeated DFL challenger Tarryl Clark by nearly 13 percentage points. This year, Bachmann faced a redrawn district that excluded Stillwater and much of surrounding Washington County and extended deep into Carver County.

Meanwhile, in six other congressional races, incumbents easily won re-election. Republican Erik Paulsen beat Democrat Brian Barnes to win a third term in the 3rd District, which includes the western Minneapolis suburbs. Democrat Betty McCollum defeated Republican Tony Hernandez and Steve Carlson of the Independence Party to win a seventh term serving the 4th District, which includes St. Paul and eastern suburbs.

Democrat Keith Ellison beat Republican Chris Fields to win a fourth term in the 5th District, which includes Minneapolis and some inner suburbs.

Democrat Tim Walz defeated Republican Allen Quist in southern Minnesota's 1st District. Republican John Kline was returned to office in the 2nd District, defeating DFL challenger Mike Obermueller.

Steve Erickson, left, checks election results on his phone while Jean Carlson, center, and Jim Graves' son, Michael, look on while attending 6th District DFL challenger Jim Graves' election party at Le St. Germain Hotel in St. Cloud, Minn., Tuesday, Nov. 6, 2012. Tom Baker for MPR

Democrat Collin Peterson defeated Republican challenger Lee Byberg in the western Minnesota 7th District.

Throughout the months-long campaign, Graves sought to portray Bachmann as a polarizing figure who focuses more on national media appearances than on the needs of her constituents.

"She's the most partisan, most polarizing person in Congress, and that's just a fact," Graves said during a debate Sunday with Bachmann on KSTP-TV. Graves, a St. Cloud native, portrayed himself as a centrist and emphasized his business experience and willingness to work with lawmakers from both parties.

The hotel magnate founded the company Graves Worldwide Hospitality and has a net worth estimated at between $22 million and $105 million, according to disclosure reports. Graves loaned $520,000 of his fortune to the campaign. In Sunday's debate, he described himself as a "fiscal conservative to the bone," adding, "I've balanced budgets my whole life."

Bachmann countered by questioning Graves' commitment to fiscal conservatism and emphasizing her own conservative credentials. The Republican incumbent frequently cited her opposition to the federal health care overhaul and to bailouts of the financial and auto industries as evidence of her convictions.

Bachmann also touted the successful passage of legislation to fund a new bridge over the St. Croix River as an important achievement. "I've done something absolutely remarkable in this last term," she said in the final debate Sunday. "I've brought Democrats and Republicans together and solved a problem that has belied Minnesota for decades."

Sixth District DFL challenger Jim Graves thanks his supporters at his election party at Le St. Germain Hotel in St. Cloud, Minn., early Wednesday, Nov. 7, 2012. The race was called for Bachmann early Wednesday. Tom Baker for MPR

Graves criticized the plan as too expensive. "A Chevrolet would've been fine. We didn't need a Rolls Royce," he said.

The candidates also differed on social issues, including abortion. Graves said he supports keeping abortion legal. Bachmann said she believes abortion should be illegal except if the mother's life is in danger.

Bachmann first ran for Congress in 2006, when Republican incumbent Mark Kennedy decided not to seek re-election. Kennedy instead mounted an unsuccessful campaign for U.S. Senate against Democrat Amy Klobuchar.

Bachmann won that year with 50 percent of the vote, defeating DFL candidate Patty Wetterling and Independence Party candidate John Binkowski. Two years later, Bachmann won re-election in a tight race against DFL candidate Elwyn Tinklenberg and Independence Party candidate Bob Anderson. Bachmann won with 46.4 percent of the vote, defeating Tinklenberg by 3 percentage points. Ten percent of voters cast ballots for Anderson.

In 2010, boosted in part by the popularity of the tea party movement, Bachmann was re-elected with 52.5 percent of the vote. DFL challenger Tarryl Clark trailed by nearly 13 percent. Anderson received about 6 percent of the vote.

Graves tried to convince voters who may have voted for Independence Party candidates in the past to support him this time.

Dan Hofrenning, who teaches American politics at St. Olaf College in Northfield, said the race was also different this year because Graves represented a new type of challenger.

"Michele Bachmann had defeated different types of candidates and I think Jim Graves is probably the fourth type. That is the successful businessman," Hofrenning said. "If she wins, she's defeated the state cabinet member, the child activist, the state legislator, and now successful businessman."