Chellie Pingree has changed from her more partisan days as a leading Democrat, in chambers comfortably controlled by Democrats, at the Statehouse in Augusta.

Perhaps that's what four years as the national head of Common Cause, a nonpartisan, open-government lobbying group, will do for you. Perhaps, too, Pingree's losing bid for the U.S. Senate has something to do with the change.

Today, Pingree is personable, a good listener and a refreshingly skeptical politician, even wary of her own ilk. She said she learned from her defeat at the hands of Sen. Susan Collins six years ago. Pingree also believes that her tenure running Common Cause will give her an unusual level of credibility, if not affection, among both Democrats and Republicans in Congress, should she win her campaign against Republican Charlie Summers.

We liked her straightforwardness.

When asked if Democratic House Speaker Nancy Pelosi is the right person to lead that chamber, into a much-needed era of bipartisanship, Pingree said: "I'm not sure that she is."

When challenged on whether Democrats would be any better than Republicans at running things and avoiding partisan faceoffs at the federal level, Pingree again said she wasn't certain but added for emphasis: "If we (Democrats) can't solve this partisan divisiveness, then we don't deserve to govern."

Pingree displays a deep knowledge of Maine and Maine issues. She can relate to problems facing small-business owners because she still owns and operates an inn on North Haven island. She's learned about the state's many other challenges because she has traveled Maine so extensively.

She's beginning to demonstrate flexibility. Once a strong supporter of a national health-care program, Pingree acknowledges that recent economic upheaval and moribund national and state economies make such a venture unlikely, both politically and financially, in the near-term.

She described the economic situation as "immediate and dire." She said working toward energy independence is a more pressing issue than universal health care, in light of the mess on Wall Street and the economy.

She displayed optimism. With its potential for wind power, wood pellets and ocean tidal and wind farms, Pingree says Maine can benefit now that the country seems to have lost some of its thirst for high-priced, Middle Eastern oil. And she notes that as people think of simpler lives in response to the economic downtown, organic and small farmers in Maine seem to be doing well, or at least better.

Her stance on energy has its weak point. Pingree clearly is reluctant to support offshore drilling for oil or building nuclear power plants. While neither, taken separately, represents a solution to the nation's energy woes, both have a role as we develop a long-term strategy for U.S energy independence.

Pingree's opponent, Republican Charlie Summers, also is a veteran of the Statehouse, where he served two terms as a senator. Likewise, he's a veteran of Washington, where he worked for nine years for Sen. Olympia Snowe. Summers has run for Congress twice before and is 0-for-2. He's worked many jobs and headed the U.S. Small Business Administration in New England.

Summers also is a combat veteran who served in Iraq from 2007-08. He stressed that, if elected, he would be one of a handful of people in Congress who would have that on-the-ground, combat experience. We believe he would use that experience well.

Summers said he would seek a seat on the Armed Services Committee, where he would keep the 1st Congressional District's 84,000 veterans in mind.

He displayed a cold-eyed assessment of what has gone wrong, and right, in Iraq, since the war began. Summers would seek to start withdrawing U.S. troops from Iraq in April 2009. He would begin shifting U.S. dollars from Iraq to Afghanistan. And he'd push for a "peace surge" in Iraq following our military effort, with Peace Corps, education, health-care and other efforts.

Summers has the misfortune of also being ready for Congress -- but he's campaigning during a year when Republicans face an uphill political challenge.

We endorse Pingree, the Democrat, for Congress. But we have a request: That she keep up her guard around Pelosi and the other Washington-beltway types, should she take office. Pingree promised to keep "what Maine needs," not what her party needs, at the forefront of her thinking, should she win. It's easy to forget that after a few months, a few years, a few terms of being wooed by the powerful in our nation's capital.

Pingree said she'll do better than that. We expect her to do so.