By all accounts, the crowd that gathered outside the temporary quarters of the Roman governor in Jerusalem on a Friday morning 2,000 years ago whipped itself, or was whipped by skilled political operatives, into an angry frenzy. The issue was what to do with a Galilean peasant who had run afoul of the carefully structured arrangement between the authorities of the occupied people and the greater authority of Rome, as represented by its appointed governor. The crowd became a mob that played a decisive role in the execution of a man innocent of wrongdoing.

Crowds can become dangerous mobs. The people in them can be swept up in anger and rage and may say and do things they would never do on their own.

Angry rhetoric on the public airwaves is also potentially dangerous. When a talk show host says, “We have to get rid of these people—these bastards,” he crosses a line between expressing a political preference and inciting violence. Sure enough, violent and potentially violent acts began to happen to politicians involved in the health-care reform bill. Is there a connection between angry rhetoric and actual violence? Is there an accountability—if not legal, then at least ethical—that everyone who speaks publicly in a free society should be held to?

I believe that the rhetoric of rage is connected to violent behavior. Our fragile experiment in republican democracy, which is based on the God-given liberty of every individual, leans heavily on the tradition of civil dialogue—and that tradition fades in the midst of shouts and threats of violence.

Columnists and spokespersons from both sides of the political divide understand what is at stake. In the New York Times, Charles Blow cites a recent report from the Southern Poverty Law Center claiming that “nativist extremist groups have increased 80 percent since President Obama took office.” In the Chicago Tribune, John McCarron writes that “while Tea Party folks have some legitimate beefs . . . they better start guarding their right flank as well as their left. . . . Some unhinged believer will fly his Cessna into an IRS office in Texas, or blow up a federal building in Oklahoma City . . .”

Wall Street Journal columnist Peggy Noonan says that there are many reasons why we have become a violent culture, but she says “one immediate thing can be done right now, and that is lower the temperature. Any way you can . . . . Just lower it.”