Pauline Hampton feeds her chickens at her home on Holiday Lake in Brooklyn, Iowa, on Thursday. Hampton, who lives next door to Democratic Senate nominee Bruce Braley's vacation home, visible in the background, has been in a dispute about her roaming chickens. (Nikki Kahn/The Washington Post)

The battle for control of the U.S. Senate could come down to a dispute between two neighbors in this heartland hamlet over four plump, wander-prone hens.

This spring, Pauline Hampton’s chickens roamed onto Bruce and Carolyn Braley’s vacation property on tranquil Holiday Lake. Hampton said she did not know this until she walked over one day to offer Carolyn a dozen fresh eggs. To which she said her neighbor replied, “We aren’t going to accept your eggs — and we have filed a formal complaint against you.”

Carolyn took her complaint to their neighborhood homeowners’ association board meeting in May. Her husband, Bruce, then called the association’s lawyer, Thomas Lacina, to say that he believed “chickens are not pets and should not be permitted at Holiday Lake,” and that he wanted to “avoid a litigious situation,” according to an e-mail Lacina wrote. Braley denied that he threatened a lawsuit.

Regardless, Hampton relented and built a wire fence in her back yard to contain the chickens. No harm, no fowl — in the Braleys’ yard, at least.

But the problem for Bruce Braley is that he’s a congressman and Iowa’s Democratic nominee for the Senate. And his Republican opponent, Joni Ernst, and her allies are seizing on the dispute to demonize Braley as an arrogant trial lawyer-turned-politician who’s anything but “Iowa nice.”

U.S. Rep. Bruce Braley, the Democratic nominee for the U.S. Senate in Iowa, in Des Moines on Wednesday. (Nikki Kahn/The Washington Post)

The chicken episode is the latest in a series of missteps by Braley that have fueled a nasty character assault against him and transformed Iowa’s Senate race into one of the most competitive in the country. Hampton, a lifelong Democrat, said a film crew with America Rising, a Republican opposition research group, recently came to her house to interview her for a possible super PAC television ad.

Braley, whose primary residence is in Waterloo, said in an interview that he and his wife handled the chicken dispute appropriately.

“At no time did I ever — ever — threaten a lawsuit or threaten litigation. Never. And anybody who says that I did is not being truthful,” he said. “This was a personal dispute between my wife and a neighbor because chickens were on our property all the time.”

He added, “I just reached out to somebody I knew expecting to get a phone call back and instead this thing blows up. And I think it’s obvious why, because people who don’t want me to be the next senator from Iowa will stop at nothing to try to drag my family through the mud.”

Dale Howe, who lives next door to the Braleys, said she made a similar complaint to the association board. “I did not think that they should be roaming around,” Howe said of the chickens. But, she added, “We didn’t have the same type of problems [the Braleys] did because they didn't leave their droppings in our yard.”

Even if Braley didn’t threaten a suit, some around Holiday Lake bristled at his tactics. “They are not neighborly,” said Hampton, a mental health therapist who uses the hens as therapy animals. “In Iowa, we are very well known for being friendly, and if one has a problem with another, we always talk to them face-to-face. This kind of floored me.”

Another neighbor, William Nagel, who sits on the homeowners association board, said, “Buddy, we’re here in Iowa. We talk like men here and we act like men. Usually, a man’s word is like gold. A handshake is a contract. Neighbors are neighbors, and if you’ve got a problem with your neighbor, you talk it out.”

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Braley, with his populist record over eight years in the House and deep fundraising base, had been considered the natural successor to retiring Sen. Tom Harkin and was heavily favored to keep the seat in Democratic hands. But heading into the campaign’s final three months, Braley is in a tough and increasingly personal fight with Ernst, who is playing up her farm-girl persona.

In Iowa, a perennial swing state that President Obama carried in 2008 and 2012, the Braley-Ernst race is a toss-up. A July NBC News-Marist poll had each candidate at 43 percent. The survey showed Obama’s approval rating at 37 percent.

In her first major interview since winning the Republican primary on June 3, Ernst said this week that Braley — a former president of the Iowa Trial Lawyers Association — is “a litigious individual” and that his character is “not the Iowa way.”

“You threaten to sue somebody because a chicken’s on your property? That’s absolutely ridiculous,” she said. “In Red Oak, my neighbor next door, when we first moved into our house, their kids were raising chickens in the garage as a project. No big deal. Oh, my goodness. It’s Iowa. Come on. Get over yourself.”

Ernst is relatively untested as a statewide candidate, and the Braley campaign is highlighting her far-right positions. The Braley team’s research shows that if the race is about policy issues — the minimum wage and other pocketbook concerns; abortion and women’s reproductive rights; Social Security and Medicare — he will fare well because Ernst’s positions are outside the Iowa mainstream.

“Her tea party ideas are wrong for Iowa,” Braley said in the interview, a point he repeated several times.

The congressman reshuffled his campaign team in June, bringing on pollster Geoff Garin and admaker Saul Shorr, who have a record of winning close Senate races. The team’s latest TV ad shows Ernst saying that she does not think there should be a federal minimum wage and that $7.25 per hour “is appropriate for Iowa” — a contrast to Braley, who wants to raise the national minimum to $10.10 and index it to inflation.

As a state senator in 2013, Ernst sponsored “personhood” legislation to amend the state constitution to say that life begins at conception — an issue Braley’s team plans to focus on in coming weeks.

“When you start filling in the details of where Ernst stands and what she’s said and what she believes, it’s a real problem for independent women,” said Jeff Link, Braley’s campaign strategist.

Asked in the interview whether she is too ideologically rigid for middle-of-the-road Iowa, Ernst laughed. “I do believe in life at conception,” she said, but noted that “we have set policy right now.”

If women “want birth control, they have access to birth control,” she added. “If women want to have an abortion, they have access to an abortion. There may be things that I personally disagree with, but women have access to those things. What I don’t believe is that all taxpayers should be paying for somebody’s personal choices.”

Ernst’s strategy is to make the race about character. And Braley has given her plenty of material to work with. During last fall’s partial federal government shutdown, Braley complained that the gym for House members was not being fully staffed. “There’s no towel service,” he said. “We’re doing our own laundry down there.”

In May, Braley was caught on video dissing Sen. Charles E. Grassley (R-Iowa) at a fundraiser in Texas. Braley warned that if Republicans win the Senate majority, “You might have a farmer from Iowa who never went to law school, never practiced law, serving as the next chair of the Senate Judiciary Committee.”

Braley apologized to Grassley, but the comment took off. It’s now a go-to laugh line for GOP presidential hopefuls when they campaign here.

Big Iowa elections historically have turned on policy differences, but Gov. Terry Branstad (R), who backs Ernst, said he thinks this one will be about Braley’s character. “He’s arrogant and he feels entitled,” Branstad said in an interview. “Iowans like just the opposite. They like somebody that’s humble, that’s hard-working, that’s a good listener.”

Ernst is trying to show that contrast. As she cut into a jumbo cinnamon roll at the famed Machine Shed Restaurant, she talked about dreaming as a second-grader of becoming a farmer’s wife (like her mom) or a nurse or Miss America.

“I am Iowan through and through,” Ernst said. She talked about her service as an officer in the Iowa Army National Guard and as a Sunday school teacher at her church. Growing up poor, she said, she wrapped plastic bread bags around her shoes when it rained because she had only one pair. And, in a dig at Braley, she said, “I don’t have a summer home anywhere.”

But Braley won’t let Ernst out-Iowa him.

“My parents both grew up on Iowa farms during the Great Depression,” he said in the interview. “I had 10 jobs between the day I graduated from high school and the day I graduated from law school — hard, tough, physically demanding work. I worked on farms when I was in junior high, I was a truck driver, a janitor, a bartender, a waiter, a cook, a construction worker. You name it, I’ve done it.”