Collins is torn over whether to leave her prominent perch as one of the Senate’s few true moderate legislators, according to her colleagues. If Collins had made up her mind by now, said Sen. Angus King (I-Maine), “she already would have announced it.”

In an interview, Collins said the buzz about her prolonged indecision is “accurate.” She initially planned to make up her mind by the end of September, but pushed back her deadline to mid-October as she wrestled with the GOP’s recent Obamacare repeal effort.

“Given the contentious environment in Washington right now, my voice and vote matter a great deal,” Collins said. “On the other hand, if I were fortunate enough to be elected governor, I could work more directly on job creation.”

She added: “That’s why it’s such a difficult decision to make. And I’m trying to figure out where I matter most.”

A Governor Collins would leave centrists like Heitkamp even more lonely in the Senate. But Heitkamp acknowledges that Collins is feeling a tug to return to Maine full time: “Fundamentally, she wants to go home.”

“She is [up in the air]. And I think she had hoped to make a decision before this,” said Heitkamp, who herself weighed retirement before announcing this year she’d run for a second term. “I desperately hope she doesn’t run.”

There’s also risk for the fourth-term senator. She could face a primary challenge in the gubernatorial race, fueled by term-limited Republican Gov. Paul Lepage’s open disdain for Collins’ opposition to Obamacare repeal proposals. And if Collins runs, it would likely fuel Democrats’ push to take back the Senate in 2020, since most Republicans believe she’s the only person from her party who can hold the seat.

In 2012, when Sen. Olympia Snowe (R-Maine) retired, King walloped the GOP candidate. So the first thing Sen. Jerry Moran (R-Kan.) did when he took over as the Senate GOP’s campaign chairman was set out to persuade Collins to run again in 2014. She won reelection with 68 percent of the vote and Republicans took the chamber for the first time in eight years.

King is begging her not to leave. And in an unusual display of bipartisanship in the Senate, so are moderate Democrats.

“She’s so important to the country here,” said Sen. Claire McCaskill (D-Mo.). “We don’t have enough folks like her.”

Republicans are fretting Collins will join retiring Sen. Bob Corker (R-Tenn.) and create a wave of pragmatic GOP senators fleeing the chamber. Though Collins holds sway as one of the chamber’s few swing votes, she also faces the frustration of watching her party constantly doing the opposite of what she’d like — from trying to repeal Obamacare on party lines, to refusing to hold a hearing on Supreme Court nominee Merrick Garland, to nominating Donald Trump.

In the latest Obamacare repeal effort, even after party leaders had written her off as an automatic “no,” she came under unyielding pressure from the White House. Vice President Mike Pence called her last Saturday as she drove across the state, a conversation that got so in-depth that Collins pulled her car over.

They talked for 40 minutes. Not even two days later, Collins came out in opposition, delivering the knockout blow. And she says another party-line shot is unwise.

“I don’t think having a partisan approach to an issue that affects one-sixth of our economy and affects millions of Americans is the right way to go,” Collins said.

Collins is reevaluating her career amid some ominous developments for a politician with her profile. Prominent deal-makers in Congress are retiring just as a new wave of strident conservatives are trying to break in. Meanwhile, Republicans say they want to take another stab next year at a party-line repeal of Obamacare, and they’re weighing doing the same thing on tax reform.

Collins would enjoy more autonomy and control over the agenda as governor of Maine, a job she sought unsuccessfully in 1994.

Asked whether she would run, Sen. John McCain (R-Ariz.) cited his surprise with Corker’s decision and said: “You never know with these people.”

“I always expect her to act in a way that she thinks is best for Maine,” said McCain, who is close with Collins and understands any aversion she might have to her current situation. “Am I happy with the environment here? Of course not. Nobody could be.”

Collins said her committee work and seniority “really matter” — but she is tantalized by the opportunity to help the less prosperous parts of the state, where shuttered paper mills and an aging population have devastated the economy.

“I’m from the northern part of the state, which needs a lot of help … two-thirds of the state is losing population and opportunity,” she said. “I have some ideas for economic development that only a governor can pursue.”

Maine Republicans say Collins would likely have to navigate the divide between the Trump and establishment wings of the Republican Party if she runs. LePage spent September slamming her opposition to the Graham-Cassidy health repeal bill as “shameful” as the two sparred over whether the bill would have been good for the state.

Phil Harriman, a political analyst and former Republican state senator, said LePage’s attacks on Collins could be damaging given his sway over the state party, though she’d be a clear front-runner in a general election.

“It would be more complicated, at least in the Republican primary,” Harriman said. “If it was today, I would say she’d probably face a primary challenge.”

Collins is cognizant of the state’s complicated political environment. In the past two decades, Maine has had Republican, Democratic and independent governors. Collins, Snowe and King have been among the most independent-minded senators in recent years. And Trump won an electoral vote in the northern part of the state, pushing Maine into swing-state territory.

Asked about LePage’s performance, Collins was diplomatic. But she acknowledged the yawning difference between her measured moderation and his bombastic sound bites.

“I support many of Gov. LePage’s policies,” she said. “Obviously, he and I have very different styles and we disagree on what the impact of what Graham-Cassidy would have been.”

While Republicans are fretting that the GOP’s flailing governance of Washington will push Collins to join the retiring Corker and Pennsylvania Rep. Charlie Dent, it’s not uncommon for senators to mull leaving the dysfunctional chamber for executive office. Most, like Heitkamp and Sen. Joe Manchin (D-W.Va.), eventually decide to stay in D.C.

Manchin was the outlier among senators interviewed for this story, who hope that Collins will stay put. The West Virginia senator said she should run if “she thinks she has a shot for it.”

“Best job in the world. Oh my god. There’s no comparison,” said Manchin, a former governor. “You never deny somebody who has that opportunity to do something good for their state.”