At 3:30 p.m. on Saturday, March 27, 2004, when I was the religion reporter (I am now its religion columnist) at the Chicago Sun-Times, I met then-State Sen. Barack Obama at Café Baci, a small coffee joint at 330 S. Michigan Avenue in Chicago, to interview him exclusively about his spirituality. Our conversation took place a few days after he'd clinched the Democratic nomination for the U.S. Senate seat that he eventually won. We spoke for more than an hour. He came alone. He answered everything I asked without notes or hesitation. The profile of Obama that grew from the...