As I step down from the chairmanship of the nonpartisan Congressional Management Foundation, I’d like to make a plea to the members of Congress whom the foundation exists to serve: that they recapture the trust of the American people.

This is not a call for the parties to play nice with each other. In a two-party system, that is rare. There are too many incentives to make your party look good and the other party look bad. Partisan jockeying that translates into votes and power can be civil, but it will not become less aggressive.

Rather, I hope each member of Congress will avoid the “tragedy of the commons” in order to regain and maintain the public’s trust.

The “tragedy of the commons” is a classic economic metaphor that can be applied to political capital. It refers to the missteps of farmers who graze their sheep on land to which everyone has access. It is in the self-interest of each farmer to maximize his use of the common grazing land to fatten his sheep.

But the collective result of such unrestrained behavior is the overgrazing and destruction of the pasture, which is ultimately devastating for all the farmers.

Members of Congress are engaged in a tragedy of the commons. It is in each member’s electoral interest to rail against the ineptitude of government and to run “against Washington.” This is frequently a successful strategy for an individual member. But it is a disaster for the standing of the institution in the public mind.

There arguably is no existential problem while the government and Congress continue to enjoy the tacit, if disillusioned, support of the American people.

But it is hubris to think this will continue forever when 99 out of 100 messages each American hears decry the competence and honesty of Washington. No major poll taken in 2011 has found more than 30 percent of Americans giving Congress a favorable job rating and several, including Gallup, showed ratings in the teens.

With the foundation of trust corroded, we risk the public having no faith in Congress’ capacity to represent the people’s interests in the event of a national emergency such as a new financial debacle or major terrorist attack.

At that crucial juncture, with their trust in Congress so low, would Americans turn to their representatives and senators to meet their critical needs for physical and economic safety? Alternatives that might seem more expedient from either the executive branch or fringe non-government actors would lead to more authoritarian, centralized government or to political and social disorder. Either would be a tragedy for representative democracy.

What can individual members of Congress do to change this in the face of the 540 others (including nonvoting delegates) over whom they have no control? Do individual members need to become patsies for aggressive electoral opponents or mealy-mouthed about their cherished beliefs and policy positions? Not at all. But language does matter.

A member can say forcefully what is wrong with a policy, program, political philosophy or an opponent’s position without tarring the institution or the government that gives him or her a platform from which to speak and act.

This requires personal commitment and rhetorical discipline. It requires refraining from populist demagoguery about Congress or the government. It requires sustained awareness that as a member of Congress you are a steward of the commons.

Where members see a need for congressional reform, I hope they state it loudly and clearly. Say it to your constituents and the media, and say it even more forcefully and courageously to your party’s leaders.

But always say it in the context that Congress is the most democratic and representative branch of the federal government. It is at the heart of the American gift to the world of self-government. And say that you serve in it proudly, at home and in Washington, even as you participate in the never-ending task of perfecting our always-imperfect human institutions.

Ira Chaleff is outgoing chairman of the Congressional Management Foundation.