It’s news when Presidents Clinton and Bush endorse the same idea. In promoting something called “social entrepreneurship” in his new book, “Giving: How Each of Us Can Save the World,” Mr. Clinton joins his successor, who cited the term approvingly in his 2005 State of the Union address. On the surface it seems like an uncontroversial, somewhat obscure term understood to mean the application of business approaches to help solve social problems. The concept has drawn praise from both the political left and right. Business schools from Harvard to Oxford even offer courses on the subject.

Yet beneath the apparent Bush-Clinton consensus, there is important disagreement about what the term, and a related movement, means. Is it a new code word for liberal causes or a useful name for a movement of idealists with limited government involvement who are helping those in need?

The term “social entrepreneur” has been popularized by William Drayton, the founder of Ashoka, an organization that provides fellowships to “social sector” innovators around the world. (Mr. Clinton now is promoting Mr. Drayton for the Nobel Prize.)

Mr. Drayton’s story — he left the Environmental Protection Agency to start Ashoka — is emblematic of a larger shift. A generation ago, the idealistic looked to government to solve society’s problems. Today, many of them have seen the failings of government programs and have decided to start their own organizations instead.

Often they have the same originality, perseverance, and big dreams that high-tech schemers in garages have, but their focus is starting big, new nonprofits. Think of Teach for America or Habitat for Humanity. Both have shown that nonprofits can reach national levels with little government funding. This success was once associated only with government programs.

Since 2001 — and again last night — the Manhattan Institute has been recognizing these kind of social entrepreneurs through an annual awards program. Luckily, we’ve had no problem finding such organizations — such as College Summit, a nonprofit that provides private guidance-counseling to help inner city kids get to college, or Upwardly Global, which helps immigrant professionals find jobs suited to their skills.

This year’s winners include a group providing free therapy, A Home Within, to former foster children that have been failed by government programs. Another organization, Reclaim a Youth, uses successful black professionals to counsel low-income black students about career options. Another group, Bonnie CLAC (Car Loans and Counseling), helps the rural poor finance car purchases instead of lobbying for public transportation spending.

But such limited government approaches to helping the disadvantaged are not the only ways social entrepreneurship is being defined. Ashoka applies the “social entrepreneur” label to Ralph Nader, Marian Wright Edelman, and Carolyn Laub, founder of the Gay-Straight Alliance, which has started hundreds of clubs to make schools safer for gay students.

The obvious danger here: that “social entrepreneur” is simply a new phrase for those who promote causes, usually liberal ones including many which have an expansive view of government’s role in providing for the social welfare. We already have names for these people: “advocate” and “politician.” Rebranding liberal activists as social entrepreneurs is a sure-fire way to alienate the right.

There’s a second kind of organization that shouldn’t be grouped under the social entrepreneurship umbrella: the for-profit firm which is called a “social enterprise.”

The Global Social Venture Competition, a business-plan contest jointly run by five major business schools, celebrates such enterprises. These for-profit groups have environmental projects like water purification systems. Such undertakings will help create a world in which, according to their literature, “every business values, generates and accounts for social impact.”

For conservatives, though, the term “social entrepreneur,” used in the context of the “social enterprise,” is actually redundant: all businesses serve a social need or they’d have to cease operations. President Bush had this right in the 2005 State of the Union in which he distinguished between the “business entrepreneur” (for profit companies) and the “social entrepreneur” (nonprofit organizations).

Making these important distinctions can help us recognize the real distinction of social entrepreneurs — those building nonprofit organizations to serve large numbers of those in need.

A generation ago nonprofits were seen, particularly by their liberal funders, as pilot projects for the government to ultimately take over. Nobody seemed to realize, much less acknowledge, that civil servants weren’t likely to replicate the dedication of such a mission that characterizes private effort. The social entrepreneurship movement now is pointing in a different direction, encouraging new organizations that want to become nationally recognized to seek private support.

Defining social entrepreneurship that way — and not as a synonym for liberal advocacy — will crucially influence whether this is a movement that will continue to command enthusiasm across political and philosophical divides or serve, instead, as a new source of divisiveness.

Mr. Husock is vice president for programs at the Manhattan Institute.