The churches are part of a national movement that began in response to immigration enforcement under President Barack Obama, who deported more undocumented immigrants than any of his predecessors. But the enforcement has intensified under Trump. According to the Church World Service — a religious ministry that helps refugees and immigrants — before last year's election, about 400 churches around the country had indicated their members were willing to offer sanctuary. After November, that number doubled to 800 and is still growing.