David Plouffe sits in his White House office, just a few steps from the Oval, staring at an oversize map of these United States. It’s late afternoon on May 9, two hours after Barack Obama’s declaration that his evolution on gay marriage has reached its terminus. The president is down the hall and on the phone, discussing his decision’s theological implications with several prominent African-American pastors—while Plouffe is being queried about its political dimensions by a querulous Caucasian reporter.