The recent retirement announcement by Sen. Olympia Snowe is a disappointment to the people of Maine and to me personally. Olympia has devoted her life to public service, and her decision to abandon a race that she surely would have won speaks volumes about the dysfunction in Congress. It has also prompted many people to ask me whether moderates have a future in the Senate.

Olympia will join the pantheon of great leaders our state has produced — Margaret Chase Smith, Bill Cohen, Ed Muskie, George Mitchell. These committed public servants understood that they were sent to Washington to solve problems, not to score political points.

But this is no longer the Senate of Smith and Muskie, of Cohen and Mitchell, and soon it will no longer be the Senate of Olympia Snowe. The change is particularly troubling in these perilous times. With a $15 trillion debt, 13 million people unemployed, oil near $110 per barrel and turmoil throughout the Middle East, there is an urgent need for leaders from the sensible center who realize that neither party has a monopoly on good ideas. The challenges we face will not be met by those who believe compromise is a dirty word.

What has been lost in recent times is a commitment to Congress as an institution, a sense that we are collectively responsible for addressing the issues that confront our country, and that if the institution fails to perform each of us bears responsibility. Just when we most need to function as a team, it appears many of us are unable to see beyond our individual self-interest or the interest of our political party.

When I was a freshman, Sen. John Chafee of Rhode Island, as fine a gentleman as has ever graced the Senate, advised me never to campaign against those with whom I serve. The Senate is too small a place for that, he counseled. Campaign for your fellow Republicans and go to states with open seats, but do not campaign against your Democratic colleagues. It will poison your relationship with them, he warned.

Most senators no longer follow the “Chafee rule.” And, yes, hyperbolic — even vitriolic — campaign rhetoric poisons relationships and makes it more difficult for Republicans and Democrats to work together.

If I had to compress all that has gone wrong in one phrase, it would be “perpetual campaign.” The gridlock in Congress and the hyperpartisan attacks that fill the Internet reflect a politics unworthy of the American people.

The increasing polarization that has prompted centrists in both parties to depart has convinced me that the center will hold only if we put the same effort into unity that partisans put into division. Predictions of a disappearing political center are a warning of a bleak future that we can avoid only by adhering to our nation’s founding principles. Yet I remain confident that principled, common-sense solutions will never go out of style and that the American people still expect government to make real progress on the issues that matter.

Indeed, there are flickerings of bipartisanship that may pull the Senate back from the brink. The “Gang of Six,” which sought last year to produce a bipartisan plan to address the debt, attracted more than 40 senators to a meeting where, one after another, senators stood up and announced that they were prepared to compromise and to take the political heat in order to deal with our unprecedented debt. It was encouraging that this group — with nearly equal numbers from each party — included not just moderates, who usually can be counted on to forge coalitions, but liberals and conservatives as well.

More recently, a bipartisan group of senators convened to discuss energy policy and committed to putting together a real plan for our country.

Just last week, Republican Lamar Alexander and Democrat Mark Pryor organized a debate on the Senate floor in which we urged our leaders to consider each appropriations bill in a way that would help restore public confidence, lead to more carefully considered legislation and restore the Senate tradition of free and open debate. Congress must avoid the spectacle of once again missing the deadline for approving spending legislation, which ultimately produces bills that are thousands of pages, while members are left with insufficient time to scrutinize their fine print and trillions in spending.

The rise of the independent voter ( 40 percent of Americans, according to Gallup) signals a deep dissatisfaction with both parties. The wide electoral swings of recent years suggest that voters have lost patience with candidates who run as pragmatists but then govern as partisans. These trends, and the embryonic signs of bipartisanship in the Senate, give me confidence that the political center will reemerge. That is, after all, where most Americans are.

Susan Collins, R-Maine, is ranking member of the Homeland Security and Governmental Affairs Committee. She also serves on the Appropriations Committee, Armed Services Committee, and is a member of the Special Committee on Aging.