Former Gov. Angus King, who is running as an independent for the U.S. Senate, said Monday that he would consider dropping out of the race this fall if it appeared that he could not win.

“I am certainly not interested in being a spoiler and changing the dynamics of the race,” King said in an interview with The Portland Press Herald. He added that he wouldn’t be running if he didn’t think he could win.

U.S. Rep. Chellie Pingree, a Democrat, said Tuesday she is still undecided and might take a few days to make up her mind.

A factor in her decision is whether a three-way general election race that includes her and King could split enough Democratic and Democratic-leaning independent votes to throw the race to a Republican.

In an interview Tuesday, Pingree alluded to the 2010 governor’s race, in which Republican Paul LePage won a close election over independent Eliot Cutler, with Democrat Libby Mitchell in third.

“That is the outcome I would not like to see,” she said.

Pingree also said that giving up the 1st District House seat in southern Maine, where she favored to win a third term, also factors into her decision now that King is in the race.

She was waiting to see a poll that was supposed to be completed Tuesday night by the Democratic Senatorial Campaign Committee and also gathering other information.

A separate poll released Tuesday by Public Policy Polling, a national Democratic firm, found that King would narrowly win a three-way race against Pingree and Republican Secretary of State Charlie Summers.

Other leading Republicans in the Senate race include former Maine Senate president Rick Bennett, Attorney General William Schneider, Treasurer Bruce Poliquin, and Sen. Debra Plowman of Hampden.

Former Gov. John Baldacci, a Democrat, is also considering running for the seat.

U.S. Sen. Olympia Snowe, R-Maine, who has held the seat since 1995, surprised the political word last week when she announced she would not run for re-election. She expressed frustration about working in the Senate, which said has become dysfunctional because of the polarization of the political parties.

King said he respects Snowe for making that decision. He said Mainers should express their frustration with party politics by sending an independent to Washington.

‘Most popular girl at prom’

King would have a clearer path to victory without Pingree in the race. In addition to the political calculation, there is a personal one: They are friends. King spent last Thanksgiving with Pingree and her her family and close friends at her home in North Haven.

King said he had called Pingree to tell her about his decision to run. He said he also wanted to give a heads-up to Baldacci but didn’t know his phone number.

Baldacci lives in the Washington area, where he is a consultant for the Pentagon on health care issues. He has said little since taking out nomination papers last week.

King said he would not bankroll his campaign with his own money. He also said he would wait until he gets to Washington before deciding whether he would caucus with Democrats or Republicans. His decision, he said, would be based on “what’s most effective for Maine,” rather than any ideological preference for either party.

Because his campaign is built on the message that political parties are causing gridlock in Washington, it wouldn’t make sense to announce now which party he would caucus with, he said.

“If I answer that question now, I would be giving up a lot on what I have said would have to sell,” he said.

King said he would expect both Democrats and Republicans to ask him to join their caucuses. If control of the Senate could be influenced by his decision, he said, he would be in a postion of power, or as he put it, “the most popular girl at the prom.”

He said Congress’s nine percent approval rating illustrates that the public believes the system is broken. “The fact that this institution isn’t working is provoking me to run,” he said.

King portrayed himself as a fiscal conservative who is liberal or moderate on social issues, such as his support for legalizing gay marriage. He said people who believe he is a “secret Democrat” are mistaken, noting that as governor, he vetoed far more Democratic than Republican bills.

Just getting started

King said he has no money in hand to run a campaign and no campaign infrastructure, other than his iPhone, which he described as his office.

His former chief of staff, Kay Rand, will run his campaign. Rand managed his successful gubernatorial campaigns in 1994 and 1998. Rand in 2010 supported independent Eliot Cutler in his bid for governor.

Since 2004, King has been a lecturer at Bowdoin College teaching a course called “Leaders and Leadership.”

He said he was teaching his class last week about Maine Civil War hero Joshua Chamberlain, a classics professor at Bowdoin who was compelled by his strong sense of duty to the nation to fight for the Union.

King said his decision to run for the senate stems from that same sense of obligation to the nation.

On some of the issues, he said is opposed to a proposed balance budget amendment, calling it a gimmick and feel-good solution.

Any efforts to reduce the federal budget deficit must include cuts to entitlement programs, King said, as well as increased revenues. He said he liked the work of the National Commission on Fiscal Responsibility and Reform, which was co-chaired Sen. Alan Simpson, R-Wyoming.

The commission proposed $200 billion in cuts in discretionary spending and $100 billion in increased tax revenues, such as introducing a 15 cent per gallon gasoline tax and eliminating tax deductions, home mortgage interest and employer-provided healthcare benefits.

“Anybody who thinks we are going to get out this deficit situation without revenues is dreaming,” King said.

He said that voting for an additional entitlement program without also identifying revenues to pay for it amounts to a tax increase on future generation, a situation he described as “inter-generational inequity.”

Pingree’s husband, S. Donald Sussman, a frequent Democratic donor, is buying a 5 percent equity stake in MaineToday Media, which owns The Portland Press Herald/Maine Sunday Telegram, the Kennebec Journal and the Morning Sentinel in Waterville and other media outlets.