Deep Pockets

David Callahan looks into what he sees as a new trend in the United States—where the wealthy are drifting to the political left. Then, discover how the great heat wave of 1896 boosted Theodore Roosevelt’s career. Also, Aamir Khan on “Peepli Live”—the first Indian film ever shown at Sundance. Plus our latest Backstory segments look at a scandal at Arlington National Cemetery, and the history and use of the filibuster in the US Senate.