The proposal to build an Islamic mosque and community center near the site of the terrorist attacks of September 11, 2001 on the World Trade Center produced widespread opposition. Although resistance among U.S. citizens was common, there was an ideological divergence, with liberals generally supporting the mosque and conservatives generally opposing it. We tested a theoretical model in which system justification mediated the effect of political ideology on level of support for the development of the "Ground Zero Mosque." Specifically, we conducted a survey of Americans near the site of the proposed mosque, and observed that, as hypothesized, greater conservatism was associated with stronger system justification, which was in turn associated with a lack of behavioral support for the mosque. These findings suggest that ideological differences in opposition to the "Ground Zero Mosque" are linked to system-justifying tendencies to preserve the American "way of life."