Echoes of Ancient Democracy in Denver

Tonight Barack Obama will address some 75,000 people on a stage featuring Greek columns like those of the White House and other buildings in Washington. President Bush used a similar set in 2004. The Obama campaign says there's no connection, though there are other reverberations. Danielle Allen, professor of social science at the Institute for Advanced Study, is author of Talking to Strangers: Anxieties of Citizenship since Brown v. Board of Education.