MOORHEAD – In the last 24 years, U.S. Rep. Collin Peterson has become a rare survivor of an endangered breed in Washington — a Democrat who sides with Republicans and works with both sides. That lonely and often frustrating stance made many believe Peterson was ready to call it quits.

But Peterson, of Detroit Lakes, said on Monday he still has the will to fight.

"There's a lot of work to be done … so I'm here today to announce that I am going to run for re-election," Peterson said, in the aging atrium of the Moorhead Center Mall surrounded by a smattering of supporters.

Whether Peterson can win re-election with the double-digit ease he has in recent years will test whether there is still a place for a moderate in the starkly partisan politics of nationalized elections.

Peterson's announcement dashed the hopes of national Republicans who believe without Peterson on the ballot, the western Minnesota district is theirs for the taking. It also gave Democrats reason for relief — without Peterson, many say they would struggle to keep the seat.

A founder of the once mighty "Blue Dog Coalition" of conservative Democrats, Peterson has seen his moderate compatriots diminish in strength and number. On Monday, Peterson trashed both Tea Party Republicans and extreme left Democrats.

"It is almost as rigid on that side as it is on the Tea Party side," he lamented. "We used to have more middle-of-the-road districts."

Re-election drama

The 69-year-old said the drama around his re-election plans was of Republicans' making. But Peterson also said that he only made his final decision last week.

His fundraising numbers, however, raised questions — he raised just $165,000 in the final months of 2013. While that haul was slightly more than Peterson usually raises, it is far less than many vulnerable members brought in.

He also fueled retirement rumors by talking openly about his views of the "foolishness" of Washington.

The former chairman of the House Agriculture Committee when Democrats were in charge, now the ranking Democrat on the committee, Peterson spent years negotiating through the details of a farm bill that only materialized last month. He had described the process as "lunacy, never-never land."

"It was almost a miracle that we got this thing done," Peterson said Monday. But he said he's healed from that turmoil.

A Republican-sponsored poll last month found that Peterson has a high approval rating in the district, but those who believed it was time for a new person to represent the district outnumbered those who said Peterson deserved re-election. A significant number said they were unsure.

State Sen. Torrey Westrom, R-Elbow Lake, has mounted a campaign to replace Peterson. The National Republican Congressional Committee, which has hammered Peterson for months, made clear even if it failed to goad Peterson into retirement, it hoped to make Peterson's re-election fight difficult.

"We have every intention of forcing him into retirement in November," said Tyler Q. Houlton, NRCC spokesman.

Calling Peterson out of touch, the NRCC said the Detroit Lakes Democrat has helped "Barack Obama's reckless agenda."

The national Republican critique, however, may ring hollow.

"Even if Democrats have a crummy year, as it is shaping up to be, I wouldn't bet a dime against Collin Peterson, "said Norman Ornstein, a congressional expert at the American Enterprise Institute.

In the 2012 election, 60 percent of voters in the Seventh District, which hugs Minnesota's borders with North Dakota and South Dakota, backed Peterson, while 54 percent supported Republican presidential candidate Mitt Romney. That made Peterson one of more than two dozen House members in a district where voters backed a House member of one party while supporting a presidential candidate of another.

But the party of the president historically loses congressional seats during the midterm elections — and, unlike Peterson, at least four other top Democrats on House committees plan to retire or opted to run for another office amid dwindling hopes they'll recapture the top spots.

Democrats need to pick up 17 seats to regain the majority in the House. Losing a veteran lawmaker such as Peterson in a Republican-leaning district would have made the task that much more difficult.

In the doorway of a Moorhead Mall jewelry store, Scott Puffe said he's a Republican who has voted for Peterson.

"I believe he is willing to work across the aisle," said Puffe, standing before the store he owns. He said Peterson has been good for the Red River Valley. But Puffe also said he supports term limits and worries that some voters are too complacent.

Even if Republicans fail in their attempt to oust him, Peterson said he does not believe Democrats will take the U.S. House this year. No matter, he said, if he wins he will continue to work with Republicans on issues that should not be partisan — at least through 2016.

"This might be my last time," he said, as his 94-year-old father looked on. "But two years is a long way away."

Star Tribune Washington reporters Corey Mitchell and Jim Spencer contributed to this report.

Rachel E. Stassen-Berger Twitter: @rachelsb