On a midweek afternoon in February 2009, a month into the Obama presidency, Republican Rep. Mike Pence arrived at Columbus in his east-central Indiana district for a town hall meeting, the sort of event that usually attracted a few dozen constituents. Surprised to see the hallway outside the room crowded with people, "their arms folded and brows furrowed," Pence shouted down the hall to an aide, asking him to get a janitor to open the room. The aide shouted back that the room was open — and overflowing. Congress had just passed the stimulus (Pence voted no), and Hoosiers were...