She says she learned the importance of hard work by age 10 while plucking potatoes from cold dirt during the harvest break in Caribou for 30 cents a barrel. Her brother jokes that she mastered compromise early on, as the middle of six children.

From potato picker to powerbroker, the GOP consensus builder who’s proved she’s willing to buck her party and who finds herself in the middle of most debates in Washington has a 20-plus-point lead over Democrat Shenna Bellows in the polls as she seeks a fourth term.

Raeleen Chapman, an auto parts store manager here in Collins’ hometown, said Collins strikes the right balance in a state where independents represent the biggest voting bloc. And she has never forgotten the rural farm country where people work hard for a living.

“She’s got a lot of respect,” said Chapman, an independent voter. “She works hard. She’s honest. She does her job well. She works for the people.”

Collins, 61, hasn’t made it easy for Bellows, winning early endorsements from national groups that might have endorsed the Democrat: the League of Conservation Voters, a major environmental group, and the Human Rights Campaign, a leading gay rights group.

She’s one of only two Republicans to get the backing of Gabby Giffords’ political action committee, thanks to her support of expanded background checks for gun purchases.

Collins also has an overwhelming fundraising advantage.

But the 39-year-old Bellows isn’t giving up.

Bellows, the former executive director of the American Civil Liberties Union of Maine, has raised $2 million, walked 350 miles to lift her profile and appeared in a TV ad with horror writer and Maine native Stephen King. She’s gone on the attack while touting her working-class roots — her father is a carpenter, her mother, a nurse — and campaigning on Democratic staples like increasing the minimum wage and protecting Social Security.

At the civil liberties group, Bellows campaigned for Maine’s successful gay marriage referendum, spoke out against the federal government’s electronic eavesdropping and supported legalization of marijuana at a time cities and states are legalizing it.

She’s quick to warn voters that sending Collins back to Washington could help the GOP assume a majority the Senate.

“Maine could make the difference between Democratic control of the U.S. Senate and Republican obstructionism,” she said.

Collins is frustrated by the attacks.

She’s been accused of opposing minimum wage, but she supports a minimum wage increase, just not as big as the one Democrats want. She bristles over claims she opposes equal pay for women, saying she successfully pressed for the Lilly Ledbetter Fair Pay Act of 2009. She doesn’t like the suggestion that she’ll tow the GOP line, noting that she’s often voted against her party.

“Saying something over and over doesn’t make it true. That’s what Shenna and her allies seem to believe,” Collins said.

Collins finds herself among a dwindling number of GOP moderates like Arizona’s John McCain and Illinois’ Mark Kirk. She’s often credited with serving as a bridge between the parties in an era of corrosive partisanship.

“People respect what she’s trying to do to bring both sides together to create change. She hasn’t gotten caught up in the partisan bickering that has split our Congress,” said Sam Collins, her younger brother.