Paris — Jean-Pierre Stirbois, a cherub-faced French printer in his late 30s, speaks in a cool, calm voice. But listen to what he has to say: ''The immigrants are the cause of our unemployment and delinquency. If you had all those Arabs in New York like us, you wouldn't accept it. We must have the political will to turn them back.''
Mr. Stirbois and his National Front party are now in a position to put some of his words into action. Running in alliance with mainstream conservative candidates, he won election this week as the deputy mayor for security in the industrial town of Dreux, about an hour southwest of Paris.
His election marks the first time in postwar France that an extreme-right candidate will hold a major post in a major town. The extreme right remains a marginal electoral force on the national level, but the success of Mr. Stirbois's virulent anti-immigrant campaign has raised fears that French politics are in danger of being radicalized.
The governing Socialists sharply criticized the decision of the conservative parties to make an alliance with Mr. Stirbois and his National Front. So did some conservative opposition leaders, and in protest Monday evening the leader of the centrist Union pour la Democratie Francaise, Michel Pinton, resigned.
''If there is a sudden shift to the right, it's a problem for all of French democracy,'' he said. ''Today it's Dreux, but tomorrow, if we don't look out, it will be the government of France.''
Most of the opposition, however, supported the alliance as a necessary measure to defeat the left. Jacques Chirac, Gaullist mayor of Paris and leading opposition spokesman, called the results at Dreux ''sanction of the majority'' and demanded the creation of a committee to construct a ''national consensus'' on the problem of immigration.
Since this call came only two weeks after the Socialist government ordered a tough new crackdown against immigration, it shows just how explosive the issue of France's 1.5 million foreign workers has become. As France's economic situation has deteriorated, no politician can afford to appear ''soft'' on the issue.
Polls show that a majority of the French believe that the best ''remedy'' for unemployment would be to send the immigrants home. Nearly 70 percent of Mr. Chirac's supporters support this action.
The National Front's support has been built on exploiting the immigrant issue. The party was founded only in 1973, just as the first oil shock was slowing down the French economy and making any new waves of foreign workers impossible for the country to accommodate.
Before 1973, of course, an extreme right existed in France. Although it had been largely discredited following the World War II Vichy government, it subsequently resurfaced among certain royalists and during the war in Algeria. But in national elections the extreme right generally polled about a tenth of a percentage point.
In the late 1970s, though, some types of extreme-right thought gained a certain amount of intellectual respectability. Some priests began preaching a traditional brand of Catholicism that played on extreme-right political themes. And the so-called ''new right'' philosophers flourished with their theories of superior and inferior races.
Despite these intellectual undercurrents, the National Front remained at the fringe of national French politics. In 1974, the front's presidential candidate, Jean-Marie le Pen, received only .74 percent of the vote. He did not do much better in 1981.
But in certain areas with large immigrant populations, the front slowly gained strength. Immigrants make up a quarter of Dreux's population. As resentment of them has grown, so has support for Mr. Stirbois.
Five years ago, in his first appearance as a candidate for the Front, he received only 2 percent of the vote. In 1982 he received nearly 13 percent. And this year he received nearly 17 percent of the vote, enough to make it impossible for the traditional conservative opposition to win without his support.
Most of Mr. Stirbois's support comes from the working-class suburbs of the city, where native Frenchmen and immigrant North Africans are crammed together into shabby modern public housing blocks. A recent visit to Dreux showed that many of these workers blame their Arab neighbors for the town's rising crime rate as well as their economic difficulties.
''They are thieves,'' a man said. ''The immigration is shameful. I have been unemployed for five years and I don't even feel safe in my own town.''
Mr. Stirbois lives in one of these blocks, and although he has a job, he represents these sentiments. His clean-cut appearance, low-key manner give him an air of respectability with his fellow workers - and with other elements in town as well.
Local Gaullist leaders such as Rene-Jean Fontainille argue that it is possible to work with men like Mr. Stirbois. ''He is not a fascist,'' Mr. Fontanille said. ''He respects the law.''
But now Mr. Stirbois will be executing the laws in Dreux, and he plans to execute them strictly, especially when it comes to immigrants. He proposes that any foreigner who is unemployed be deported. And he says that any foreigner who commits even the slightest crime will be sent home.
''The Arabs want to throw us into the sea,'' he said. ''Unless we fight back , they will succeed. I represent the popular current that is ready to fight back.''