She has been the go-to girl for legislators seeking to build bipartisan coalitions in Congress.
But with the surprise retirement of Maine's Olympia Snowe, one of the last moderate Republicans in the Senate, the era of across-the-aisle constructiveness fades further into the past.
Ms. Snowe, 65, who has spent a combined 34 years in Washington in both chambers of Congress, announced on Tuesday night that she will not seek a fourth term in the Senate this year.
The news hit hard in the capital, where everyone immediately knew the subtext of her decision.
"I have had to consider how productive an additional term would be," Ms. Snowe said. "Unfortunately, I do not realistically expect the partisanship of recent years in the Senate to change over the short term."
With Ms. Snowe's departure in January, the Senate will become a lonelier place for her Maine GOP colleague Susan Collins, who often crossed the aisle with her.
Indeed, several of the upper chamber's centrist players will not seek re-election in 2012. They include conservative Democrats such as North Dakota's Kent Conrad and Nebraska's Ben Nelson and independent Connecticut Senator Joe Lieberman.
Their voluntary departures follow the involuntary ones of Republicans who could not survive primary challenges from their party's right wing during the 2010 midterm elections. That includes Utah's Robert Bennett and Mike Castle, the ex-Delaware congressman who lost the GOP Senate nomination to Christine O'Donnell.
The result is a record degree of polarization in the Senate, which had long been considered a collegial body where party identification was a secondary consideration in passing bills.
Now, it comes first and foremost, making it an insufferable and stifling place for people like Ms. Snowe.
Indeed, though she ultimately voted against President Barack Obama's health-care reform bill, her decision to support an early version of the legislation allowed it to proceed beyond the committee stage to the Senate floor.
As much as Ms. Snowe's GOP colleagues often found her too liberal for their liking, they are sorry to see her go. She was a likely shoo-in for re-election. But without a strong GOP candidate in the wings, her seat could now go to a Democrat, further reducing the likelihood that Republicans can take control of the Senate in 2012.
In announcing her decision not to seek re-election, Ms. Snowe deplored the "my-way-or-the-highway ideology" that has become pervasive in American politics and its governing institutions.
There is speculation that she could join a new group, Americans Elect, that is considering launching a third party that would unite centrist Republicans and Democrats.
Such efforts have not gained much traction in the past. But with the approval rating of Congress hitting single digits, something has to give.