Over the summer two stars of the American right had a friendly argument about who poses the greatest threat to the United States. Fox News host Bill O’Reilly went with the conventional wisdom: al-Qaida. During the Bush administration, it was the clash of cultures that organised the way American conservatives saw the world. When they worried about issues like illegal immigration, what they were afraid of was al-Qaida operatives mingling among the future valet parkers of Chicago and meatpackers of Iowa. But O’Reilly’s new colleague and ratings rival, Glenn Beck, had a more surprising answer: it’s not the jihadists who are trying to destroy our country, it’s the communists.