President Obama embraced diversity as far back as last August when he hugged Charlotte Mayor Anthony Foxx, who he has now nominated as Transportation Secretary.”

At Saturday night’s White House Correspondents’ dinner, Conan O’Brien joked that President Obama’s hair is now “whiter than his Cabinet,” but today’s announcement that Charlotte Mayor Anthony Foxx is Obama’s pick for Transportation Secretary made that joke fall flat.

The White House noted that the president’s choice to replace outgoing Secretary Ray LaHood, is a Black man, whereas LaHood is White. The administration noted that Foxx spoke at the Democrat National Convention “as an African-American.”

The Republican National Convention immediately tweeted: “What’s up with Obama’s #WarOnBlackMayors? Another one bites the dust.”

But the White House said critiques of the president’s record on race are unfair.

“The fact that Mayor Foxx is only the first black appointee of the second Obama administration doesn’t overshadow the president’s longstanding commitment to diversity,” said spokesman Jay Carney, who is White. “The president has no bias against African-Americans. In fact, some of the president’s best friends are Black.”