In 1964, just one congressman from the Deep South, Atlanta's Charles Weltner, voted for the Civil Rights Act. For all practical purposes, his righteous leadership on civil rights — he also supported the Voting Rights Act — cost him his congressional career. In 1966, he resigned his seat rather than sign an act of loyalty to the segregationist Lester Maddox, as Georgia Democrats insisted. But some analysts believe he would have lost the race for re-election. Doing the right thing is difficult because it often means losing. And the typical politician is willing to lose anything — honor, integrity, dignity...