Religions in the election campaign

A week before the federal elections, debates have been taking place in German-speaking Switzerland about the burka. The Valais UDC ran an advertisement in "Le Nouvelliste" with the headline: "Etat islamique, bientôt chez nous?". In a secularized society where the place of religions no longer seems to be a matter of debate, why does fear of Islam still remain a campaign argument?