The French, who are too intellectually proud to borrow political ideas, are trying to reinvent Reaganism, discovering, with an impudent air of originality, the case for tax cuts, decentralization, the market, entrepreneurship -- the whole package. Although France is ripe for a Ronald Reagan, the frothy political system has churned up only a George Wallace, a person gifted as a political lightning rod for gathering and concentrating grievances, but implausible as a national leader.

He is Jean-Marie Le Pen, a burly ex- paratrooper who lost an eye in a political brawl in the streets in 1958, and who says that "the Afro-Asian threat" of immigrants to France is the "vanguard of the barbarians storming the West." Last year, when his party drew more than 2 million votes, a Paris headline asked: "Are There 2,182,248 Fascists in France?" The answer is: No, but there are at least that many people who are in a surly mood about the presence of 4 million immigrants, especially those from North Africa.

One of Le Pen's slogans is a stroke of mischievous genius: "My program is what you are thinking." His aim is to make it acceptable to proclaim things that people hitherto have only thought, such as: France is being "invaded and submerged" by immigrants.

Posters about the battle of Dien Bien Phu, where Le Pen served, are sold at his rallies. He has sued publications that have said he tortured Algerians during the war, but it is unclear that the charge has hurt him with his followers.

When he says "Parisian salons" misunderstand "the real world," he is banal. But he has theatrical flair. When word reached France's foreign minister at a meeting of Third World officials that Andropov had died, the minister proposed a moment of silence. This enraged Le Pen, who, during a television interview, asked why not a minute of silence for victims of communism, and proceeded to stand and stare into the camera for a minute while his interviewers babbled and the nation watched, mesmerized.

If his National Front is not to be considered fascist, he should stop talking about uniting "all the forces of the nation in a fasces." One of his colleagues says, "The Jews have a tendency to occupy all the key posts in Western countries." It is said that when Madame Simone Veil, a popular French politician and a survivor of Auschwitz, was mentioned at a National Front rally, the crowd chanted, "Veil back to Auschwitz."

Le Pen and his movement are unpleasant manifestations of many things, including xenophobia and the dissolution of old ideological clarities. The four communist ministers have left Francois Mitterrand's government, and the Communist Party now proclaims itself the only authentic voice of the left. But that is less a boast than a dreadful confession that leftism is in disrepute. Once France's largest party and a vehicle for protest votes, its popularity is lower than at any time in half a century.

Reality has dragged Mitterrand's socialist government so far right that moderate conservatives are having trouble complaining convincingly, which is half the fun of politics, and 98 percent of the fun of opposition. When socialism becomes watery wine, some supporters of right-wing parties slide farther right to acquire a more distinctive identity.

Furthermore, Le Pen is a consequence of socialism, or at least severe statism, in another sense: he has been produced by slow economic growth. When the job market is stagnant, as Europe's has been for years, slow growth makes economic life seem like a zero- sum game in which anyone's gain must be a proportionate subtraction from someone else's well-being. In such circumstances, people become bitter about "outsiders" getting in the game.

France's economic stagnation is in large measure a result of the suffocating weight of the omnipresent and omniprovident state, which has grown to disastrous proportions imposing compassionate judgments about the allocation of wealth and opportunity. So Le Pen is an ugly little chapter in the history of the doctrine of unintended effects -- the doctrine that the unintended effects of social policies sometimes are opposite to, and more important than, the intended effects. Le Pen, and the national irritability that has produced him, is, in part, a consequence of the compassionate impulse in politics.