W.E.B. Du Bois' classic 1903 work The Souls of Black Folk opens with "The problem of the Twentieth Century is the problem of the color line." Du Bois helped form the NAACP, the National Association for the Advancement of Colored People, which just celebrated its 100th anniversary.

Henry Louis Gates Jr., who directs Harvard University's W.E.B. Du Bois Institute for African and African American Research, knows much about the colour line -- not only from his life's work, but from life experience, including last week, when he was arrested in his own home.

Gates' lawyer, Harvard Law professor Charles Ogletree, said in a statement that the arrest occurred as Gates returned from the airport:

It's a shame that Judge Sonia Sotomayor, the Obama nominee for the U.S. Supreme Court, chose not to defend her statement "I would hope that a wise Latina woman with the richness of her experiences would more often than not reach a better conclusion than a white male who hasn't lived that life" at her nomination hearings this week.