SESTO SAN GIOVANNI, Italy — The leaders of this blue-collar town marked an antimigrant milestone with a pistachio layer cake last week. To commemorate what they said was the 200th migrant expelled from their town, they wrote the number on top with green frosting.
As Italians vote in national elections Sunday, many of them share the migration-skeptic swagger of the right-wing leaders of Sesto San Giovanni.
Italy is struggling to accommodate the more than 620,000 migrants who have arrived on its shores since 2013, and a new sentiment is gaining force: Boot them all out.
Ex-prime minister Silvio Berlusconi, whose center-right coalition appears to have the best shot at victory Sunday, has promised to defuse what he called a ‘‘social bomb ready to explode in Italy’’ by deporting 600,000 people.
His coalition partners, including a group descended from the remnants of the Fascist Party, are even more vociferous toward the migrants, most of whom are from sub-Saharan Africa.
Italy’s choice Sunday could ripple throughout Europe because the country is the continent’s main migrant gateway. The European Union, already weakened by Britain’s decision to leave the bloc and the electoral setbacks of Chancellor Angela Merkel of Germany, is watching the Italian vote warily.
Sesto San Giovanni has volunteered its crackdown on migrants as a blueprint for the country.
‘‘Sesto has become a model, a point of reference for the nation, that is showing you can rule and make changes against urban decay,’’ said Mayor Roberto Di Stefano, 40, a member of Berlusconi’s center-right Forward Italy party.
Di Stefano’s cellphone buzzes continually with messages from the constituents to whom he freely hands out his personal contact details — a contrast, he said, with his hard-to-reach center-left predecessors.
The town of 83,000, which abuts Milan, was once called the Stalingrad of Italy for its communist leanings. It had elected left-wing leaders since World War II, until the anti-immigrant campaigners swept into office this past summer.
The new leaders captured the sentiment of voters at a moment when unemployment remains stubbornly high and Italians are asking why they are spending money to support migrants when they themselves feel vulnerable.
‘‘This city was at the mercy of crime,’’ Di Stefano said. Now, he said, ‘‘We are the first-place municipality in Italy when it comes to expulsions.’’
After becoming mayor, he empowered police to press charges for minor quality-of-life violations, such as panhandling, and pressed them to be more aggressive in checking the papers of people they suspected of being in Italy illegally.
He also forced an end to plans for a mosque inside town limits that would have been the largest in the region. Now, he is talking about licensing Israeli CCTV technology in a project that would mount 62 cameras around the town and use facial recognition to monitor people coming and going.
‘‘We did the same as Giuliani did in New York City in the days of zero tolerance,’’ said Claudio D’Amico, a member of the far-right Northern League party who is in charge of security issues in the city government. ‘‘If you want to turn Italy into Afghanistan, then we have a problem.’’
As the mood in Italy has soured toward migrants and refugees, national leaders have scrambled to catch up. Politicians sometimes appeared to be in an escalatory war of toughness during the pitched campaign, bringing positions traditionally favored by the far right into the mainstream.
In Sunday’s elections, the Northern League, which popularized many of the antimigrant ideas, stands a chance of besting Forward Italy, its more centrist coalition partner. Of all the possible outcomes, that could lead to the harshest consequences for migrants.
‘‘Some people would prefer to pray on the Koran, a religion where women have fewer rights than men. Where they preach hate from mosques. I don’t want that,’’ Northern League leader Matteo Salvini said at his final rally in a residential area of Milan on Friday. ‘‘We need to defend our borders and our workers.’’
In a measure of the souring attitudes toward immigration, Berlusconi still counts as a moderate inside Italy even though his goals for mass deportations would require a level of coercion not seen in Western Europe since World War II. The sharpest objections have come from well outside the political mainstream.
‘‘No country can ever catch, detain, and expel 600,000 people,’’ said Riccardo Magi, the secretary general of the Italian Radicals, a left-wing party unlikely to clear the bar to enter parliament.
Refugees in Sesto San Giovanni say they have noticed the tougher climate in Italy. While he waited for a bus recently, Issa Diagouraga, 26, a refugee from Mali, said national police in three squad cars stopped to watch him.
‘‘They don’t stare at others the way they stare at me,’’ Diagouraga said. ‘‘It’s like they wanted me to feel the difference between being an Italian and a foreigner.’’
Other refugees said they feared the outcome of the elections.
‘‘They’re talking very badly about immigrants, and they say that if they win, a lot of things will change for us. They’re using immigrants to win more votes,’’ said Lamin Jarju, 19, a refugee from Gambia.
But they both said they hadn’t noticed any specific changes from the new approach by the mayor’s office, an account echoed by others who work with migrants and refugees in the area.