In the fall of 1989, Rev. Ralph Abernathy came out with a memoir about his time as a close aide to Rev. Martin Luther King Jr. Abernathy told the tale that Rev. King committed adultery with two women on the night before he was murdered. On NBC’s "Today," Bryant Gumbel, then a co-host of NBC's Today, lectured: "When the truth collides with a legend, print the legend." When Abernathy noted that King's exploits were "common knowledge," Gumbel retorted, "It would better stated, perhaps, to say that it was common accusation." He claimed that those pages "just as easily could have been left out ... one could argue that your writings prove nothing." All this came to mind on March 18, when The New York Times came out with an investigative report that Mexican-American labor leader Cesar Chavez, another "civil rights icon," had not only committed adultery, but reportedly forced himself on girls as young as 12. Chavez died in 1993.…