At the height of the "Obama is a Kenyan" lunacy, an unusual meme -- even by the standards of the birthers -- began making the rounds.

According to the know-nothings who populate that nutty alternate universe, President Barack Obama was born in Kenya, but he was most likely the son of slain black nationalist leader Malcolm X.

Sure, the mind boggles at the mental gymnastics it takes to argue that Mr. Obama is Malcolm X's son based on the dubious observation that the two men "look alike."

Why base a theory of progeny on DNA or even a random strand of reality when old-fashioned racist paranoia gets you to that point faster than any evidence? If the Nebraska-born Malcolm X is really Mr. Obama's father, as the theory proposes, that would clearly make the president an American. So much for being a Kenyan usurper.

And if Malcolm Little El-Hajj Malik El-Shabazz is his father, it's also an indication that the president has taken his legendary aloofness to the next level.

In July, Attorney General Eric Holder told the National Association of Black Journalists that the Justice Department would not reopen the investigation of Malcolm X's assassination despite calls from activists and historians who insist only part of the story is known.

"Although the Justice Department recognizes that the murder of Malcolm X was a tragedy, both for his family and the community he served," the DOJ said in a statement, "we have determined that at this time, the matter does not implicate federal interests sufficient to necessitate the use of scarce federal investigative resources into a matter for which there can be no federal prosecution."

That's cold when even the president of the United States isn't interested in finding out who really murdered his "daddy."

Whatever one thinks of the merits of reopening cold cases from the civil rights era, there are a lot of murky corners in the Malcolm X saga that could stand another round or two of declassified FBI documents and legitimate investigation. Serious scholars and historians unearth fascinating evidence every year pointing to an actual conspiracy and living, indictable scoundrels.

Those disappointed by Eric "America is a nation of cowards" Holder's dismissal of the Malcolm X case shouldn't take it personally. When it comes to revisiting the criminal cases of black historical figures, the Obama administration is nothing if not consistent.

Last month, the Obama administration refused the petition for a presidential pardon for the black nationalist leader Marcus Garvey. The founder of the Universal Negro Improvement Association was imprisoned for a $25 mail fraud scheme that most historians believe was a federal government frame-up designed to derail the black nationalist movement.

Because the Jamaican-born Garvey was one of the most powerful black leaders in the country at the time, he attracted the attention of a federal agent named J. Edgar Hoover. The agent, who would later become the director of the FBI and torture generations of black leaders, helped put the case against Garvey together.

A Justice Department spokesman said recently that a posthumous pardoning of Marcus Garvey would be "a waste of time" since the back-to-Africa movement leader had been dead for decades. It's that kind of blazing insight from a government official that makes one nostalgic for previous presidents who weren't afraid to pardon black folks convicted of crimes under questionable circumstances.

Still, Garvey was no angel. His kind words about the Ku Klux Klan after a series of secret meetings with them in the 1920s, and his unkind words about Jews and Catholics on the jury that convicted him, made a pardon by the Obama administration problematic. I understand that.

There's no excuse, however, for refusing to pardon Jack Johnson, the first black heavyweight boxing champion, who was convicted of transporting a white woman across state lines.

Sen. John McCain, R-Ariz. and Rep. Peter King, R-N.Y., co-sponsored a resolution that passed a contentious Congress in 2009 with bipartisan support. It should have been easy for Mr. Obama to sign a pardon for a genuine African-American hero. For their part, Obama officials say that they don't pardon dead people.

If a black president can't fight for Jack Johnson even when white conservatives give him political cover, what will he fight for?