Bernie is not the new black. Black Lives Matter activists made this apparent when they took to Twitter over the weekend, spawning the satirical hashtag #BernieSoBlack in response to what many saw as the Democratic presidential candidate's attempt to "whitesplain" racial inequality from the perch of white privilege.

Sanders, the Vermont senator who has been a surprising runaway hit with millennials and progressives since announcing his campaign, weathered heavy criticism for appearing to gloss over the subject of race and the Black Lives Matter movement as he spoke at the Netroots Nation 2015 conference in Phoenix, Arizona, over the weekend.

Can all you black people at Netroots Nation shut up so Bernie Sanders can whitesplain civil rights to you? — Kris Banks (@KrisBanks)July 18, 2015

Racism and biased policing have been at the forefront of America's conscience in the last 12 months, so it's no surprise that at an annual convention for liberals and progressives, activists held aspiring presidential candidates to their report cards on civil rights.

While he may not have exited stage left as Maryland Gov. Martin O'Malley did when he was heckled by crowds over the same issues at the convention, Sanders's gruff reaction to protesters who demanded he recite the names of black people who had died at the hands of police or while in police custody still sparked a stiff social media scolding.

As protesters began chanting "say her name," in reference to the recent death of Sandra Bland in a Texas police cell under what her relatives said were suspicious circumstances, and "Black Lives Matter," Sanders contemplated cutting short his address before speaking up.

"Black lives of course matter," Sanders said. "I spent 50 years of my life fighting for civil rights and dignity, but if you don't want me to be here, that's okay. I don't want to out-scream people."

Sanders, a self-described democratic socialist, then continued to talk about income inequality and the economy — central themes of the senator's presidential campaign and career.

Shortly after the event, activists took to social media to condemn what they perceived as Sanders essentially shucking racial inequality in favor of income inequality. The senator, who comes from America's second whitest state (after Maine), later attempted to convey that the two subjects are inextricably linked when he spoke of racial discrepancies in education and unemployment, which he linked to an overburdened criminal justice system.

"Black people are dying in this country because we have a criminal justice system which is out of control, a system in which over 50 percent of young African-American kids are unemployed," Sanders said. "It is estimated that a black baby born today has a one in four chance of ending up in the criminal justice system."

But many contended that black and white poverty are disparate, and cannot be lumped under or smoothed over by a single liberal economic agenda, no matter how progressive. Some accused Sanders of folding race and civil rights into his broader talking points on the economy without specifically addressing the "crushing consequences of structural racism" and speaking the "names of the people who have been killed by a powerful, racist system."

Bernie had a chance to show his commitment to — Zack Ford (@ZackFord)July 19, 2015

The social media digs continued through the weekend, accompanied by the hashtag #BernieSoBlack, which was introduced to the Twittersphere by Roderick Morrow, a host of the comedy podcast Black Guy Who Tips. Morrow used the hashtag to spoof the pushback against the criticism in the Black Lives Matter movement among Sanders supporters, in which they insisted that he was in fact a longtime advocate of civil rights and racial inequality.

Little known fact Bernie Sanders was actually the one who told John Carlos and Tommie Smith to put up black power fist in 68 — Rod TBGWT (@rodimusprime)July 19, 2015

The hashtag soon began trending in tweets that have ranged from tongue-in-cheek to serious political and social commentary.

Others called out those they believed had missed the meaning behind the verb "whitesplaining" entirely. Various definitions have described it as a patronizing way for whites to explain to people of color the true nature and forces behind racism.

We'll have a whole chapter called: 'Actually white people cannot, by definition whitesplain to OTHER WHITE PEOPLE' — Adam Johnson (@adamjohnsonNYC)July 20, 2015

The hullabaloo has opened a rift between Sanders supporters and others who also see themselves as liberal and progressive.

Instead of attacking the guy who fought for Civil rights with — Bipartisan Report (@Bipartisanism)July 19, 2015

I won't apologize because you EXPECT black folks to usher in your candidate, no questions asked. — Leigh (@RichieLeigh)July 19, 2015

Later Saturday evening, Sanders returned to the stage in Phoenix before the largest crowd of his presidential campaign so far. This time, he spoke more directly about the issues of police accountability and racism raised earlier in the day.

"When a police officer breaks the law, that officer must be held accountable," he told a crowd of roughly 11,000. "Let us be clear, while we have overcome a lot of racism, we still have a long way to go."

His public relations team also rushed to pull Sanders out of the quagmire.