Caricature artist John Kascht discusses celebrity, image-making, and his portraits of Alan Greenspan and Warren Buffett that are currently on view in the exhibition "Twentieth Century Americans." Kascht has published work on the pages of GQ, Times, and the New Yorker. The National Portrait Gallery has 23 of his portraits in its collection. Recorded at NPG, December 11, 2010. Image: Alan Greenspan / John Kascht / Watercolor, colored ink and graphite on paper, 1999 / National Portrait Gallery, Smithsonian Institution; copyright John Kascht