Democratic presidential candidate Barak Obama’s appearance before a large evangelical congregation in Orange County over the weekend underscored an evident imperative of his campaign: Emphasize his Christian faith and put to rest insistent rumors that he secretly adheres to the Islamic creed of his father and youth. The effort to minimize any grounds for fearing Obama has an abiding, if covert, attachment to Islam has prompted him to risk offending Muslims in order to avoid off-message controversies and photo ops. It is, therefore, curious in the extreme that he is giving a prominent role at next week’s Democratic convention to...