Professor Henry Louis Gates Jr. had a very bad day. After a long trip home from China, where he was filming his new PBS documentary, “Faces of America,” the Harvard professor was probably looking forward to a little rest. Instead, he was arrested outside of his own Cambridge, Massachusetts home.

The official reason for his arrest, in the language of the police report, was “loud and tumultuous behavior,” something The ATLANTIC’s Jeffrey Goldberg notes he might exhibit as well, “if the police were arresting me in my own house — for breaking and entering into my own house.”

That may be true, but Gates broke two cardinal rules for success while Black in America (something Soledad O’Brien may not have time to cover in this month’s CNN special). Rule Number One: Don’t get angry. Rule Number Two: Don’t get angry when police are present. Case in point: The BOSTON GLOBE reported that the “normally-mild-mannered professor” become irate when, according to the police report, an officer suggested he come outside of his home to discuss the dispute. “Ya, I'll speak with your mama outside,” Gates allegedly said. When police asked for identification, the report says the professor became visibly upset and asked, “Why, because I'm a black man in America?''

Of course, Gates knows the rules. He knows them so well that he writes books about them for a living. So why did he lose his cool? Well, according to initial reports, Gates’s trip to China had left him “sick” and “exhausted.” The man was tired, and he lost his temper.

The particular kind of outrage swirling around Gates’s arrest is silly. “Henry Louis Gates Jr. Arrested. Seriously, Cambridge?” Carolyn Kellogg asks in the LOS ANGELES TIMES. Sure, the arrest of the prominent scholar is an especially egregious case of racial profiling. But it’s also a snapshot into what it’s like to have a very bad day as a black person in America.

Two years ago, another prominent American explained the experience: “As a black man, Barack can get shot going to the gas station,” Michelle Obama said in a CBS interview in early 2007, when concerns were raised that running for president while black could pose certain risks.

Her point? The daily indignity of racism is that black people cannot expect to live their lives as most Americans do.

In our “post-racial” age, it’s uncomfortable to think of the victims of racial profiling as people like Henry Louis Gates Jr., whom The ROOT interviewed from his Martha's Vineyard home. But at least one blogger wasn’t surprised. “I bet he did exhibit 'loud and tumultuous behavior,'" said Ta-Nehisi Coates. “I likely would too. Actually, I wouldn't. But I don't work for Harvard. And my mother taught me how black men are to address the police,” Coates quipped. Even the most prominent black Americans who forget this will pay a price.

—MARA GAY