I suspect that the broadest American constituency to be found under any single label this year is the one wearing Calvin Klein jeans.

The fact is that we are absolutely sheep-like in following fashion, but we have become a bit sheepish about following politics. We're ashamed to be seen wearing a political label that doesn't fit or that someone has convinced us is terribly dated.

In any case, being a liberal today is like wearing a crumpled corduroy suit at a dressed-for-success corporate meeting.

By 1979, you are told, you should have moved right along. You should have joined the rest of the with-it folk who are worrying about how SALT II is contributing to the breakup of the American family, and how the new narcissism is responsible for low college-board scores.

Instead, there you are, you old-fashioned liberal, no doubt still reminiscing about Adlai Stevenson and privately listening to records of Pete Seeger singing "This Land is Your Land."

Liberals, especially so-called liberal "thinkers," are peculiarly vulnerable to political attacks due to a congenital case of qualms. Liberals wear qualms like elbow patches.

A liberal with qualms is, I am told, supposed to be a new conservative. Or so I am told by conservatives. But not all of them are willing to go quite that far. They would rather do a bit of custom alteration.

George Will stopped in the midst of quoting Santayana, Plato and Henry Adams in his column the other day to wonder whether they would have to come up with a neo-designation, i.e., neo-liberal.

But, in fact, liberals today remind me of a favorite Woody Allen line. When asked his religion he replied, "Jewish. . . with reservations."

I think that if you gave a multiple choice to most New Deal, New Frontier and Great Society supporters, they would describe themselves today as "Liberal. . .with reservations." The Liberals With Reservations may, for example, believe in the programs to help the poor, but be totally frustrated by the bureaucracy administering them. They may still want to reduce the gap between the haves and have-nots, but be horrified by the layers of people and paper work standing between the ideals and the poor. They may see their goals stuck in a thicket of despair.

The Liberals With Reservations may also believe that it's essential for society to deal with children's needs. But again, they may see those needs defeated by programs set up to help them. Whether the issue is foster care or day care, the big government many counted on for solutions has produced its own problems.

The Liberals With Reservations may still approve of an idea, but be appalled by the perverted reality. Even those who support the notion of school breakfasts, for example, can be driven to fury when they see a school breakfast of sugared cereal or doughnuts.

There are, in the same vein, many who are deeply disturbed at an America in which so often "livin' is a thing that money can buy." They may want a comprehensive medical health plan for the people, but worry about the restrictions, the costs, the intrusions.

They may, in short, be "liberal" in terms of their vision of a better-cushioned, or more equal, society, but with grave reservations about the way to accomplish these goals.

It's popular to say that liberals are playing possum, or on the defensive, or turning right. It is, at least, very popular among Liberals With Reservations. They write their own obituaries with a passion surpassed only by their own "reformed" soul mates, the neo-conservatives.

The new conservatives often point to the problematic programs as proof that the liberal ideals are bankrupt, passe, old-tattered-fashioned. But the Liberals With Reservations don't make the same leap. They aren't turning on their visions but on their methods. And this, I suspect, makes them ripe for renewal. It is easier to rewrite the directions than the goal, easier to find a new map than a new prophet.

So, if it's true that the "old" liberals are wearing their tattered qualms in public, it doesn't look to me like a permanent fashion.