Carlson engages with Jonathan Rauch as to why the rush toward this grandest of social experiments, gay marriage. Rauch, author of The Case for Gay Marriage, counters that gay marriage is a cause even conservatives can support. Richard Cohen of The Washington Post and Zanny Minton Beddoes, The Economist's economics correspondent, join Tucker on this week's Plus 2 to discuss the politics and consequences of gay marriage. Americans are increasingly placing form over function, choosing style over substance. Carlson discusses with Virginia Postrel, author of The Substance of Style, this distinct trend. Postrel, a noted observer of American culture who writes the ""Economic Scene"" column for The New York Times, explores with Carlson the burning question: do we really need a designer toilet brush?