Terry Gross

Michael Tanner is director of Health and Welfare Studies at the libertarian think tank the Cato Institute. He launched the Project on Social Security Choice at the institute, which first looked at the possibility of turning the system into a private savings program. He supports Bush's Social Security plan.

Economist and New York Times columnist Paul Krugman. A professor of economics and international affairs at Princeton University, Paul Krugman opposes Bush's Social Security plan, and has written about it in his columns. He's also the author of Fuzzy Math, on the Bush tax cut.

Boyden Gray is the chairman and founder of the group Committee for Justice, formed to promote conservative judicial nominees. Gray was instrumental in getting Clarence Thomas appointed to the Supreme Court. Wednesday, we heard from Ralph Neas of the liberal group People for the American Way.