Minnesota's congressional candidates spent the first hours after their primary victories plunging into expensive and heated contests.

Candidates began barnstorming their districts, patched up wounds with rivals and started scouring the political landscape for new donors necessary for this relentless push toward Election Day.

"This is going to be a dogfight," DFL Party Chairman Ken Martin said of the closely watched congressional race in northern Minnesota's Eighth District.

U.S. Rep. Chip Cravaack, the freshman Republican in the district, which Democrats around the nation are vowing to win back, began a two-day tour of the area Wednesday morning, hitting five cities and visiting countless small businesses, reinforcing his focus on the local economy.

His well-seasoned DFL challenger, former U.S. Rep. Rick Nolan, gathered with his primary rivals in a Duluth union hall and spoke with a single, unified message: We must bring down Cravaack.

In Minnesota's southernmost congressional district, Democratic U.S. Rep. Tim Walz will face former legislator Allen Quist, a Republican who prides himself on being an unflinching conservative crusader.

After a decisive primary victory, Quist now says he is focused on meeting residents and on raising the money necessary to win.

The Eighth District race offers Democrats one of their best chances to pick up another seat in the U.S. House, a situation that will likely open the spigots for national cash.

But this is a grudge match for Republicans, too. They are out to prove that Cravaack's shocking 2010 victory over longtime Democratic Rep. Jim Oberstar was the result a profound and long-lasting ideological shift in what was once one of the nation's most reliable Democratic strongholds.

Already, outside groups have poured more than half a million dollars into the district -- and that was before the DFL race was settled in a messy three-way primary.

Martin told party members on Wednesday that they cannot assume the race is in the bag just because the party historically has had a lock on the district's political power. That kind of thinking, he said, cost them the seat two years ago.

Yet, Cravaack is in an enviable position. He has collected more than $1 million in contributions and hardly spent anything while the DFLers were slugging it out. Fresh from the primary, his fundraising dwarfs Nolan's. The DFLer, who has been out of elected politics for 30 years, had less than $90,000 in the bank, according to his last report.

Cravaack, a devotee of Republican vice presidential candidate Paul Ryan's stringent budget proposals, has proven politically savvy in picking up a union endorsement, which shocked some outside GOP observers, but which could prove a crucial boost in a district known for its strong union ties. That, too, has Democrats nervous that this fight will be grinding, expensive and uncertain.

"[We've] gotten some blow-back from Democrats and other labor groups, but I've had very good conversations with our members, which is most important to me," said Jason George, legislative and political director for the operating engineers union, Local 49, which endorsed Cravaack.

Democrats are feeling more comfortable about their chances to keep Walz representing the southern First Congressional District.

"The choice is clear and, in November, southern Minnesotans will vote for Tim, who has stood up for middle-class families, veterans, students and seniors," said Sara Severs, Walz's campaign manager.

Republicans picked Quist to take on Walz, a former schoolteacher seeking a fourth term.

Like Nolan, Quist is a product of a different era. During the primary campaign, his opponent, state Sen. Mike Parry, bashed Quist's past statements comparing counseling for gays to the KKK and saying men had a genetic predisposition to head households. Those and other statements recently earned Quist a spot on the pop culture website BuzzFeed's list of the eight craziest candidates in the country.

But Quist said Wednesday that was all left behind when 54 percent of First District GOP voters preferred him.

"The public has said we really are not concerned about things that may or may not have been said 20 years ago," he said.

Republicans are now forging ahead with their own brand of unity in the sprawling First District.

Parry told supporters Wednesday that "it is imperative that we do everything we can" to make sure Quist defeats Walz.

Quist has accepted Walz's invitation to debate at least three times, plans to attend a Saturday night Republican endorsing convention and is turning his attention to fundraising.

"It is a lot easier to raise money after the primary," said Quist, who has largely self-financed his run until now.

Republican U.S. Senate candidate Kurt Bills, who had the GOP endorsement and now has its nomination, found the political skirmish of a primary challenge actually made it easier to raise money.

Republican candidate David Carlson ran cable ads this month accusing Bills of clinging to the more controversial beliefs attached to Texas U.S. Rep. Ron Paul, a libertarian-leaning Republican and Bills supporter. After that, the money started flowing into the Bills campaign, said campaign manager Mike Oss- kopp.

But Bills' conservative support is not as strong as Republicans would like. He garnered 51 percent of the vote Tuesday, causing some Minnesota Republicans to doubt his viability against the popular fundraising dynamo, Democratic U.S. Sen. Amy Klo-buchar. Carlson got 35 percent and frequent candidate Bob Carney got another 14. Carlson even topped Bills in the Seventh and First districts and nearly did so in the Eighth.

Osskopp said Republican doubters' obsession over those numbers is "ridiculous."

"We won by 16 points without spending a nickel on the primary," Osskopp said. "Every nickel we have spent and every minute we have worked has been focused on Amy Klobuchar."

Rachel E. Stassen-Berger Twitter: @rachelsb