A little over a decade ago, I met Bernie Sanders when I was a pimply-faced undergrad interning in his Washington office. I was attending college at a small liberal arts school in South Carolina, and I desperately needed a change of scenery, and his was the political voice I related to the most at the time.

I needed to be around voices that ran counter to the toxic patriotic bravado that had consumed America in our post-9/11 world. Our gung-ho attitude was about to result in disastrous foreign policy decisions, and unprecedented infringements on civil liberties. Too many Muslim Americans were targets of unjust abuse as a fear of foreign “brown” people consumed the country, and this hit home to me as an African American even if the abuse was not directed at me. When I flew to D.C. to start my internship in 2003, I was still stopped and taken aside for a more thorough security check at the airport. My complexion and my beard had made me a potential threat to the state. Our world was getting out of hand, and I wanted to work for a voice of reason, so to the surprise of many I decided to intern for a socialist from Vermont.

I do not think my mother even knew who Sanders was at the time, and the few people who did found his disheveled hair to be more memorable than his political views. Sure, they knew that he was staunchly against the war in Iraq and championed civil liberties and civil rights, but they really wished that he would comb his hair more. Countless others I encountered were intrigued that a black male from the South would want to work for a white Yankee left-winger. They assumed I would have chosen to work for a black congressman and they wondered what we might have in common on issues both political and personal.

Over the weekend this same scenario escaped the confines of my undergraduate world and took center court on the national stage as #BlackLivesMatter protesters disrupted Sanders and fellow Democratic presidential candidate Martin O’Malley at the progressive Netroots Nation conference.

Black protesters chanted “What side are you on, black people, what side are you on!” while O’Malley spoke. The protesters lobbed questions at both candidates regarding their civil rights records and they wanted to know if each of them would work to “dismantle structural racism in this country.”

O’Malley responded with an affirmative “Yes” and later said, “black lives matter, white lives matter, all lives matter,” to a chorus of boos.

Sanders, when it was his time to speak, took the stage saying, “I don’t want to out-scream you,” and he then proceeded with his previously planned speech as the protesters continued to interrupt him. He bristled with discomfort at questions about his civil rights record and eventually he addressed the protesters, saying, “Black people are dying in this country because we have a criminal justice system that is out of control.”

As moderator Jose Antonio Vargas was unable to control the crowd, Sanders asked him, “What are we doing here?”

These protests surprised many at the conference, and Sanders’s befuddlement, shock, and frustration reminded me of the bizarre responses I received from others when I first decided to intern for him. There was a disconnect and an assumed incompatibility between the black community and Sanders despite the fact that both have similar positions on most issues.

This disconnect can lead people to question the civil rights record of someone with a 100 percent voting record, according to the NAACP’s congressional report card.

During the 1960s Sanders participated in sit-ins fighting racial segregation, so he has been fighting against racial injustices for longer than many of the people who protested him have even been alive. Yet still over the weekend, #BernieSoBlack was trending on Twitter and mocking his activism.

This is the dichotomy Sanders faces. He has a long track record of fighting for civil rights, but he primarily has only needed to express these facts to white audiences. His messaging does not appeal to black voters, and most—like my mother—have no idea who he is or what he has done until someone else tells them about him.

Vermont is this bizarre state that cares about the issues that are important to African Americans while also being nearly devoid of black people. The state is roughly 95 percent white. Of Vermont’s nearly 630,000 inhabitants, only 1.2 percent are black.

This is a difficult situation to explain. How can a senator care about black people without having nearly any black people in his state? Electorally, he has never been accountable to black voices.

If Sanders wants to sustain his momentum and have a fighting chance of becoming the Democratic presidential nominee, he must show that he not only relates to African Americans on the issues that matter most to them, but also that he can relate to them on a personal level.

Hillary Clinton has already displayed her ability to win over black voters in her successful Senate campaigns, and no one can doubt Bill Clinton’s appeal to African-American voters. Many black families still talk about his fabled appearance on The Arsenio Hall Show playing the saxophone.

Sanders has thus far surprised many with his packed auditoriums full of supporters and his competitive polling against Clinton in Iowa and New Hampshire, but if he wants to be considered a serious challenger, he needs to be competitive in South Carolina. Success in South Carolina requires winning over black voters.

There is time for Sanders to do this, and the current Democratic front-runner has already shown that her support among African Americans is not as steady as one would think. The rapper Killer Mike, who has been a significant voice in the #BlackLivesMatter movement, has recently endorsed Sanders, so this is a step in the right direction.

The chaos at Netroots Nation this weekend made it clear as day that Sanders has a mountain to climb to win over black voters. Despite Sanders’s long record of civil-rights advocacy, black voices question his credibility because he has never needed to prove himself to this community. Being a champion of civil rights within a bastion of white America holds little sway with black voters.

A decade ago, Sanders was the voice I needed during a transformative time in America, but I was an anomaly within the black community. He’s going to need to convince way more African Americans that he is the right person to fight for their issues if he wants even a sliver of a chance of winning the Democratic nomination.