When Johnson decided to fight for passage of the law John F. Kennedy had put before Congress in June 1963 banning segregation in places of public accommodation, he believed he was taking considerable political risks.

Whatever the long-term legal prospects for same-sex marriage, President Obama's willingness to put the matter front and center in an election year can at least make him a candidate for inclusion in Kennedy's Profiles in Courage.

Obama's endorsement of gay marriage is hardly as consequential as Johnson's legislative success on civil rights.

Robert Dallek Quotes