Effective leaders -- successful CEOs, presidents and legislators -- get tough things done and can effect epic defining change, because they have that "X-factor." An intangible quality and peculiar charisma -- something apart from a trenchant understanding of the issues and technical competence -- that motivates people to follow, accept discomforting choices, and overlook shortcomings in their background or character. John Kennedy and Barack Obama possessed it, and each was elected with few legislative accomplishments and virtually no executive experience. Similarly, it permitted Bill Clinton to overcome Jennifer Flowers. Mitt Romney has an admirable track record as a governor and...