Somewhat buried among all of the other important revelations to emerge from President Obama's brief trip to South Africa (selfies, handshakes, interpreters) was a photo showing Obama raising his fist in what we think of as the black power salute. Meaning that long-standing conservative fantasies of a philandering, anti-white, Communist president all got some fodder over the 36 hours he was there.

Obama's secret racism

Media Matters' Oliver Willis tweeted the photo taken at the Nelson Mandela Memorial Service on Tuesday.

The idea on the (relatively far) right that the Obamas harbor secret, roiling hostility to White America is not a new one. In 2008, a subset of his opponents focused on reports that Michelle Obama had at one point used the word "whitey" in a never-discovered video. It was a rumor so ridiculous that even rumor-friendly Michelle Malkin dismissed it. In both 2008 and 2012, Obama was linked extremely tenuously and unconvincingly to the "New Black Panther Party," a small group of men with a worldview that is vocally hostile to whites. There are far more rumors than that, of course; it's simple to trace much of the more extreme opposition to Obama back to issues of race, as The Wire did in September.

AP

The photo shared by Willis hasn't circulated widely — at least, not yet. Perhaps that's because it's an obvious reference to the Mandela's African National Congress. It's so closely associated with Mandela that the cover of this week's New Yorker shows Mandela, fist upraised. Or perhaps the image hasn't circulated widely among conspiracy theorists because they've been focused on other things.

Obama's secret Communism

The handshake between Obama and Cuban leader Raul Castro inspired more than 40,000 news articles this week, according to a quick search at Google News. Forty thousand including our own, which was explicit in making the joke about Obama sending a signal about his Communist leanings. Others, like Rush Limbaugh, weren't as obviously joking.

The idea that Obama is a communist or socialist is a long-standing one, bubbling up during his first run for the presidency. It became more concrete in his famous exchange with Joe the Plumber in 2008, but it was always there. For what it's worth, actual Socialists are quick to disown Obama.

Obama's secret philandering

The extensively analyzed interaction between Obama and the attractive prime minister of Denmark — the taker of the now-famous selfie — plays on a more subtle idea: that Obama has a wandering eye.

In 2010, the National Enquirer ran an item suggesting that Obama had an affair with a campaign staffer. There was no evidence beyond that story, which the White House denied. More recently, the emotionally disturbed woman who was shot to death on Capitol Hill after having rammed a barricade at the White House evolved into a conspiracy theory that she was Obama's mistress, who'd arrived in Washington to confront the president. There is, of course, no evidence of this at all.

The New York Post's Andrea Peyser extended that assumption to the selfie.

In front of 91 world leaders, the mourning nation of South Africa and Obama’s clearly furious wife, Michelle, the president flirted, giggled, whispered like a recalcitrant child and made a damn fool of himself at first sight of Denmark’s voluptuously curvy and married prime minister, Helle Thorning-Schmidt.

As MSNBC's Irin Carmon noted on Wednesday, there are racial overtones to the brouhaha, that Obama is an "over-sexed black man." But it's mostly a reflection of America's willingness to have its biases confirmed. Half of America expects the president to want to give a black power salute in order to insult white Americans, so they see that picture as confirmation. And the other half of America expects that knee-jerk response, and so they look for it. The president, by doing things that a president does, can't help but toss coal into both fires.