Four years after he first entered the White House, there’s no longer anything surprising about calling Barack Obama—America’s first black president—a “transformational” leader. Yet the full extent of Obama’s transformational potential has yet to be realized in one realm: his biracial heritage.

Obama’s 1995 book Dreams From my Father makes clear that his identity was influenced as much—if not more—by his Caucasian mother than his absentee African father. But since he won the Democratic nomination in 2008, both Obama and the media seem to have shut the closet door on his multi-culti background. With his black wife and children by his side, Obama certainly represents an aspirational—and much-needed—African-American cultural ideal. But with one half of his family history so conspicuously overlooked, whether by circumstance or design, that ideal is not the entire story of his identity.

“To a certain extent, I think it’s been an act,” San Francisco State University Professor Andrew Jolivette—editor of Obama and the Biracial Factor, a collection of essays—says of the president’s mono-racial messaging. “The president has been afraid to speak more openly about being biracial because it could be read in so many different ways.”

Indeed, both blacks and whites seem equally uneasy with more complex views of Obama’s ethnic origins. Cornel West and Jesse Jackson, for instance, have both suggested that Obama is somehow not black enough. And with African-American voters perceived as hostile to the Obama-as-biracial narrative, touting the President’s Caucasian other half could easily have cost him crucial election support. “There’s a political constituency for African-American voters, which is why Obama wanted to present himself as a black candidate,” says Stanford Law Professor Ralph Richard Banks, author of Is Marriage for White People?. “There’s not much of a political constituency for a biracial candidate.”

Yet whites, too—particularly the mostly white mainstream media—have been noticeably quiet on this topic. Back in 2008, New York Times columnist Nicholas Kristof raised the issue, asking, “Should we call Obama ‘black’ or ‘biracial’?” Though he declined to answer the question himself, he observed that “the convention in America has been that someone who is biracial is considered black, and that’s the standard that we in the news media generally hew to.”

With so few journalists actually asking the president about being mixed race, Obama has conversely had very little to tell them. Or maybe because he’s so publicly—and repeatedly—identified as black in the past, the president simply feels he has nothing left to reveal. “Some might suggest he’s purposely not talking about it, but perhaps his mixed heritage is no longer some ongoing restless question for Obama,” suggests Michele Elam, professor in the department of English and the Center for Comparative Studies in Race and Ethnicity at Stanford. “I don’t think he’s repressing his mixed heritage or capitulating to the ‘one-drop’ rule,” Elam continues. “For Obama, the choice to identify as black has never been merely about biology or blood ... He sees blackness as containing differences of experience and ancestry.”

But whether or not Obama continues to struggle with his identity, it remains an important topic for many Americans. Last summer, Morgan Freeman said that Obama is “not America’s first black president—he’s America’s first mixed-race president.” More recently, several stories have struck hard at the racial amnesia that has mostly defined our perception of the president.

More than 1.8 million Americans identified as mixed black/white in the 2010 census—an increase of 134 percent over the previous decade. Overall, more than 9 million Americans identified as biracial—up 34 percent from 2000. As this cohort matures in both age and influence, Jolivette suggests that they could more aggressively claim the president as their own. “There’s a feeling among some mixed people that they’ve been cheated out of a hero,” he says.

Obama, too, has been cheated in the process—robbed by political necessity of the opportunity to speak to the multiracial reality increasingly defining America. Nonetheless, the president’s biracial origins and cosmopolitan, culture-rich past seem to inform much of his upcoming agenda—from immigration reform to economic equality. Which arguably makes now the perfect time for Obama to finally realize his transformational potential on this topic by speaking more about it.

“Overlooking or ignoring the fullness and complexity of Obama’s ethnicity keeps this conversation stagnant and very 20th century,” says Jolivette. “And Obama wants nothing more than to truly be a 21st-century president.”