Earlier this month, I announced on Twitter that I planned to report on the disconnect between Democratic presidential candidate Sen. Bernie Sanders (I-Vt.) and black voters. Immediately, some of Sanders’s self-described supporters raided my mentions with patronizing tweets.

Over the past few months, Sanders’s predominately white backers have used Twitter to target any black activist or journalist who dares question the candidate’s civil rights record. The battle reveals a long, simmering racial divide in the progressive movement that continues to go unacknowledged. If Sanders wants to win black voters, he’ll need to address it.

A series of Gallup polls this summer found that Sanders has a +13 favorability rating among African Americans, compared with Hillary Clinton’s +68 favorability rating. There are many reasons for Sanders’s poor polling with African American voters: his unknown name, the limited diversity of his home state, his shaky response to interactions with Black Lives Matter protesters. But the social media battles have shown that Sanders’s supporters also have become a major hurdle for the candidate in building a positive image with the black electorate.

The online clashes between some of Sanders’s white supporters and black voters came to a head after protesters interrupted the senator’s speech at Netroots Nation in July, demanding he speak candidly about police brutality. His defenders took their anger to the Web, with condescending blog posts and combative tweets that have continued unabated since:

They accused black activists of being agents of Sanders’s opponents:

They blamed black Americans for Sanders’s disconnect from black communities:

They accused voters who question him of being racist:

And they insisted black voters give Sanders unquestioning support:

Of course, it’s not fair to blame Sanders for the vitriol of trolls. But at a time when he’s trying to build a relationship with black voters, his supporters can have a significant effect on his image.

Political consultant L. Joy Williams says Sanders could have won the allegiance of some black voters by responding to his supporters’ combative and patronizing comments and distancing himself from them. It would have been a good opportunity for the candidate to interact with black press and connect with black Americans, she said. “It’s not as if he went on NewsOne Now or did an interview with black press and said, ‘I am dismayed by the way some of those who support me are treating us [black voters].’ That never happened.”

The go-to defense for Sanders’s supporters is to mention the candidate’s involvement in civil rights protests in the 1960s. The implication is that black Americans owe their votes to Sanders today because he did the right thing by supporting black Americans’ rights 60 years ago. This patronizing position not only assumes that black Americans are one-issue voters, but also that their one issue has been solved for five decades.

Roderick Morrow, who runs the comedy podcast “Black Guy Who Tips,” responded with the hashtag #BernieSoBlack, mocking the argument that simply marching with Martin Luther King Jr. makes Sanders black Americans’ ideal candidate.

Marching with King is not a coronation to the black vote, nor was his endorsement of Jesse Jackson’s presidential campaign. Many people reasonably question whether Sanders’s message of fixing economic inequality will benefit African Americans. The revolting tone of the backlash to critiques of Sanders’s record on racial issues is the digital manifestation of a historical divide  between black Americans and white progressives. From the labor movement of the post-industrial era to the feminist movement of the 1960s, people of color long have been sidelined and patronized when they try to exercise their voices in progressives spaces that claim to welcome them.

Black Lives Matter activists shut down a rally by Democratic presidential candidate Bernie Sanders in Seattle. (Reuters)

More recently, this lingering racial divide appeared in New York City’s Occupy Wall Street Movement, which I covered for TheGrio in 2011. Each evening in Zuccotti Park, young men and women took to the mic, lamenting the greed and excess of the 1 percent at the expense of the 99 percent. Though the movement was leaderless, the voices most often heard were those of white men and women. Dozens of nonwhite organizers grew so tired of being shut out of strategy meetings that they formed a “People of Color Working Group” to assert their presence and express their grievances of economic racism.

Occupy focused on class struggle, while economic racism — the systemic ways in which racism limits economic opportunity for people of color was barely acknowledged or outright ignored. Across the country, people of color were present in Occupy, but a study of the movement’s racial representation found that African Americans made up just 1.6 percent of its participants.

Sanders’s message, like that of Occupy, generally deals with economic inequality. While he has spoken about how economic inequality affects communities of color, that’s not the same as articulating the words “economic racism” and addressing the friction between black and white progressives.

It’s true that Sanders understands the economic ills of America like few others in Congress. But he’s done little recently to show that he understands the particular ways those ills affect black Americans. It’s unclear how they should see themselves in an America run by President Bernie Sanders.

That is the conundrum he needs to address. Fast.

Democratic presidential candidate Bernie Sanders spoke before a large crowd in South Carolina, telling voters that his progressive agenda will benefit African Americans and other minorities. (AP)

Sanders’s team seems savvy with social media — he effectively live-tweeted the GOP debate with a nimble combination of snark and intellectual depth. So it’s puzzling why his campaign has yet to use the platform to tweet about the racial animosity many black people feel emanating from his progressive base. Instead, Sanders has allowed these online rifts between his supporters and black users go unchecked. Or, for that matter, unacknowledged.

Will having a Twitter chat about racism in the progressive movement improve Sanders’s polling numbers? Likely not. The campaign’s challenges of earning black support are more expansive than social media. But there would be one less conflict for Sanders to navigate if black voters could see he doesn’t approve of the behavior of some white progressives who support him.

If he wants to see an exponential increase in black support, Sanders will have to prove to black voters that the world he envisions will be as beneficial to them as it will be for the mostly white progressives who support him. And that means he’ll have to unpack the lingering racism of the progressive movement.

More from PostEverything: