One line that caught my attention in Obama’s Q/A with the House Republicans last Friday was his rationale for toning down the demonization of one another. He argued, for example, that when Republicans portray him as someone out to destroy the country (i.e., health care reform is a Bolshevik plot), it radicalizes their constituencies and ultimately limits their ability to engage in any bipartisan efforts with him to deal with the country’s problems — lest they be accused of being an accomplice with a socialist.

Audience costs don’t come as a surprise to many of us in IR. James Fearon’s 1994 APSR piece articulated the concept and suggested that because democracies would likely have higher domestic audience costs than authoritarian regimes, they would be able to make more credible threats. Michael Tomz has elaborated on the theoretical mechanisms and developed stronger empirical evidence showing how audience costs actually shape and constrain elite behavior. Focusing on national security issues, Tomz finds that domestic audiences are concerned with reputation and credibility and routinely punish leaders who say one thing but do another thing.

I found it interesting that Obama made these references last Friday — the same day Tony Blair defiantly testified before the British Iraq Inquiry. Audience costs don’t constrain elites who are true believers like Blair who continues to hold that Saddam Hussein posed an existential threat to global society. He told the Inquiry: “I believe he was a monster, that he threatened not just the region but the world.”

But, I’ve argued that domestic audience costs did have an effect on Bush’s U.S. domestic mobilization for war against Iraq. The legacy of a decade of demonization of Saddam Hussein throughout the 1990s opened the political space for President Bush and the Neocons to maneuver the US towards a preventive attack on Iraq. Several of the Democrats who voted to authorize the war in Iraq in October 2002 were clearly uncomfortable with their vote, and yet, they feared a public backlash a month before the mid-term elections. That backlash wouldn’t have happened without their own participation in the decade-long rhetorical conditioning that Saddam Hussein posed an existential threat to the United States — they couldn’t oppose war with Iraq without the risk of seeming to coddle a tyrannical dictator hell-bent on destroying America.

Obama’s caution — that demonization of your political opponent could very well box you in — is certainly worth noting whether it pertains to domestic politics or international diplomacy.