Cardinal Timothy Dolan says Donald Trump's rise in popularity marks the re-emergence of an ugly ideology.
In a Daily News op-ed, Dolan says nativism has returned to the national stage thanks to the real estate mogul and Republican presidential hopeful.
He defines nativism as the belief that immigrants are dangerous and that America is better off without them.
Trump continues to take heat for his comments about Mexican immigrants last month.
In the column, the cardinal compares Trump's campaign to the KKK in the 1920s.
He goes on to say, "I am not in the business of telling people what candidates they should support or who deserves their vote. But as a Catholic, I take seriously the Bible's teaching that we are to welcome the stranger...As an American, I take equally seriously the great invitation and promise of Lady Liberty."