But such incendiary views about a world religion now find wide expression in the United States where “stealth jihad” has become a recurrent Republican theme.

Several Republicans, including former House Speaker Newt Gingrich and Representative Peter King, have found it politically opportune to target “creeping Shariah in the United States” at a time when the middle name of the president is Hussein. (A Newsweek poll last year found that 52 percent of Republicans agreed with the statement that “Barack Obama sympathizes with the goals of Islamic fundamentalists who want to impose Islamic law around the world.”)

I spent time last year with Paul Blair, a pastor in small-town Oklahoma, a state where Islamophobia is rampant. He told me Muslims were “not here to coexist but to take over.” He told me there are only two possibilities in Islam — “the house of Islam or the house of war.”

That sort of message is going out in a lot of U.S. churches. It’s dangerous. Already, Muslims are victims in 14 percent of religious discrimination cases when they make up 1 percent of the population.

In Europe, too, rightist politicians peddle divisive anti-Muslim bigotry, with some success.

Muslims have work to do. They should have the courage to denounce unequivocally the Mazar murder. Jihadists have too often deformed a great religion with insufficient rebuke. From Egypt to Pakistan, it must be understood that Islam cannot at once be a political force and above criticism. Once you enter the democratic political arena on a religious platform, your beliefs are no longer a private matter but up for legitimate attack. Pakistan’s violence-inducing blasphemy laws are an affront to this principle.

Jones, by contrast, lives in a nation where the law defends even his folly. I’m a free-speech absolutist and so I support that. But he must examine his conscience: How is it consistent with religious faith to stir hatred and killing? And how can the Islamophobes, spreading poison, justify their grotesque caricature of Islam in the thinly veiled pursuit of political gain?