Attorney General Lori Swanson jumped into the DFL primary for Minnesota governor on Monday, immediately shaking up the contest between state Rep. Erin Murphy and U.S. Rep. Tim Walz and complicating the Democratic effort to hold onto the state's top political job.

Swanson announced her plans at a hastily arranged, 20-minute news conference in Minneapolis. At her side was U.S. Rep. Rick Nolan of northeastern Minnesota, her newly minted lieutenant governor running mate.

"We're a couple of problem solvers. That's what I've done as attorney general, is to try to solve big problems on behalf of the people of Minnesota," said Swanson, citing the recent $890 million settlement with 3M over contaminated drinking water in the east Twin Cities metro.

A three-term attorney general, Swanson was unable to secure the DFL endorsement in her re-election bid at the party's state convention on Saturday. Her last-minute shift to the governor's race promises to intensify what already looked to be a competitive primary between Murphy, the DFL-endorsed candidate and state lawmaker from St. Paul, and Walz, a six-term congressman from southern Minnesota.

The political re-sorting rattled many DFL insiders as they prepare to defend a seat that Gov. Mark Dayton has held for eight years, and rumors flew throughout the day of further candidate shuffling ahead of Tuesday's 5 p.m. deadline to file for the Aug. 14 primary ballot. On the Republican side, former Gov. Tim Pawlenty will face off against the GOP-endorsed Hennepin County Commissioner Jeff Johnson, with Pawlenty an early front-runner thanks to name recognition and fundraising success.

Swanson mulled a run for governor for months until announcing earlier this year that she'd run for re-election as attorney general instead. But that plan derailed at the DFL convention in Rochester when Swanson fell short of endorsement on the first ballot. She dropped out, leaving delegates to endorse Minneapolis lawyer Matt Pelikan instead. A political newcomer, Pelikan ran on a platform of being a strong progressive voice.

Swanson's recruitment of Nolan potentially ends his planned political retirement before it starts. Previously a congressman from 1975 to 1981, Nolan came back in 2012 to win the increasingly competitive Eighth District through three elections. But he announced a few months ago that he would not run again this year.

Nolan said he and Swanson could "find that common ground and fix the things we can fix, and make sure the people of Minnesota have good jobs and good health care, and children have good education."

Swanson, 51, who racked up more than a million votes in her last two races, brings immediate advantages to the race. She has spent nearly 12 years scoring headlines and TV coverage by suing companies accused of fraud and other malfeasance, including bill collection firms, for-profit colleges and most recently an opioid manufacturer. Because she's never been in Congress or the Legislature, she does not have a lengthy voting record to attack like Walz and Murphy, who have both been lawmakers since 2007.

Both Swanson and Nolan are likely to make appeals to DFL voters outside the Twin Cities, and older voters who are the most reliable in primary elections. Swanson has not openly courted progressive support in the same way as Murphy and Walz have.

"I think they have the potential to do well on the Iron Range," said Rep. Rob Ecklund, DFL-International Falls.

Some DFL operatives see a downside in nominating a ticket too strongly tied to the Twin Cities. On Monday, Murphy's running mate, state Rep. Erin Maye Quade of Apple Valley, faced that dynamic when she was initially unable to answer a question from the Forum News Service about E85, the gasoline-ethanol blend that's an important part of Minnesota's agricultural economy.

Maye Quade later took to Twitter to clarify: "I misspoke. I know how important E-85 is to the state's economy and the livelihood of Minnesotans."

Swanson is joining the race late, without the grass-roots infrastructure that Murphy and Walz spent months and hundreds of thousands of dollars building in advance of the convention. Nolan endorsed Walz earlier this year, as the Walz campaign pointed out in a news release Monday.

"We welcome any newcomers to this race," it said.

Murphy picked up a big-name backer Monday in Gov. Mark Dayton, following her underdog win for the DFL endorsement on Saturday. "I have seen firsthand Murphy's transformative leadership," Dayton said in a news release.

In response to the Swanson announcement, Murphy released a statement: "We continue to build momentum by focusing on a new kind of politics based on what unites us as Minnesotans, not the same divisive playbook of the past."

With a weekend of endorsing conventions behind them, candidates for both parties launched into the next phase of the campaign Monday with a flurry of news conferences, fundraising work and barnstorming tours around the state. One possible DFL primary candidate dropped out Monday: State Auditor Rebecca Otto, who finished behind Murphy and Walz for the DFL endorsement, suspended her campaign.

Republicans fan out

In St. Paul, the GOP's slate of endorsed candidates appeared at a news conference where they vowed to "make Minnesota red." Johnson said he would travel the state to win over independent voters and new voters who turned out in 2016 to cast their ballots for President Donald Trump.

Pawlenty spent the day flying around the state, with stops in Moorhead, Duluth, Rochester, Mankato and St. Paul. He applauded Swanson's decision to bypass her party convention, as he did as well. He said contested primaries are a better way to choose candidates than political endorsing conventions, because many more voters are involved.

"This is noisy and it's fun," Pawlenty said. "It's good, it's raucous. I think it's going to be interesting for voters, I think it's going to be interesting for the state. It's going to be interesting for the Democratic Party and for the Republican Party. What the hell, let's have some fun."

Johnson called Pawlenty's tour out of touch, saying he'd make his own trips in his Jeep, or eventually a small RV. Pawlenty did not mention Johnson.