Politicians and pundits often scorn polarization and compromise--the intransigence of the former and the feebleness of the latter--without suggesting an alternative way. Polarization, when opposing forces are equal or close to equal in strength, leads to stalemate. Compromise threatens to betray one's conviction about what is essential. Ideally, a leader must combine conviction about what ought to be done with an open-minded awareness of unintended...