Once, while I was teaching at a Southern college, African-American student leaders attended a faculty meeting to explain some of their frustrations with us, including some faculty’s expectations that individual black students speak on behalf of African-Americans more generally. Ten years later, in the coffee obsessed upper left-hand corner of the country, a student of mine pressed a classmate to explain the black perspective on the topic at hand. I intervened and explained why “She doesn’t have to answer that.” After class she thanked me for the time out.

Following the release of Do the Right Thing, I remember watching an interviewer pressing Spike Lee to explain the meaning of contrasting MLK Jr. and Malcolm X quotes at the film’s conclusion. He sidestepped the question, saying that film is art, and therefore open to different interpretations. I could tell he resented the question, probably thinking most filmmakers wouldn’t have been asked it.

Three refreshingly different African-American opinion leaders’ reactions to Obama’s recent comments about Trayvon Martin serve as an excellent reminder that there’s more diversity within ethnic groups as there is between them. Seems like a simple point, but it’s often lost on people. Consider each.

1) Tavis Smiley, Sunday on Meet the Press, after previously tweeting, “Obama’s speech was weak as pre-sweetened Kool-Aid.”

I appreciate and applaud the fact that the president did finally show up. But … he did not walk to the podium for an impromptu address to the nation. He was pushed to that podium. A week of protests outside the White House, pressure building on him inside the White House, pushed him to that podium.

2) Charles Ogletree, National Public Radio:

It was the most refreshing, startling and amazing comment I’ve ever heard him make in the 25 years I’ve known him on the issue of race; very poignant, very personal . . .

3) Eugene Robinson, The Washington Post:

The designation ‘first black (fill in the blank)’ always brings with it unfair burdens, and one of Obama’s. . . is that almost anything he says about race will be seen by some as favoring the interests of black Americans over white Americans.

At this point in his presidency, Obama could ignore this absurd reality and say whatever he wants. He must be sorely tempted. But the unfortunate fact is that if his aim is to promote dialogue about race, speaking his mind is demonstrably counterproductive.

Obama does more to change racial attitudes and challenge prejudices simply by performing his functions as head of state and commander in chief. A dozen speeches about the long struggle for racial equality and justice would not have the impact of one picture of the first family — the proud, African-American first family — walking across the White House lawn. No caption necessary.

Near the end of his comments, Obama encouraged people to think about whether they are “wringing as much bias out” of themselves as possible. Borrowing from King, he suggested asking, “Am I judging people as much as I can, based on not the color of their skin, but the content of their character?”

One element of “content of character” thinking is acknowledging, if not embracing, intellectual diversity within ethnic groups.