When Democratic Party leaders "found God in the 2004 exit polls," as Washington Post columnist E.J. Dionne Jr. likes to say, no one expected instant results. Many of the party's early efforts to attract religious voters, after all, were scattershot and not a little awkward. No one knew quite what the "faith staffer"—a new breed of legislative aide—was supposed to do, and random-seeming insertions of Bible verses into floor speeches came off as Tourette's syndrome for Democrats. In the longer run, though, the new focus on forming relationships with religious communities and voters has been the right move for a...