ATLANTA — The room was electric.

Thousands packed a Bernie Sanders rally at Morehouse College, a historically black campus. This is where the Vermont senator wants to bring Southern black voters into this "political revolution."

Surrounded by a diverse crowd of mostly young supporters, Sanders predicted that he would "surprise people" here in Georgia, and perhaps in neighboring South Carolina where he campaigned earlier in the day.

Sanders promised the crowd that he's the candidate who could best combat institutional racism and reform police departments around the country.

"Together we are going to end the horrors that we have seen time and time again on TV of unarmed African-Americans being shot and killed by police officers," Sanders said.

"We love you Bernie," a woman yelled as the applause died down.

See also: Bernie Sanders just released a powerful new ad featuring the daughter of Eric Garner

Sanders formally kicked off his tour of historically black campuses on Tuesday, an effort his campaign announced earlier this year as it looked ahead to contests where voters of color play a significant role. Campaign officials said more than 4,800 people attended the rally.

While Sanders launched few direct attacks on rival Hillary Clinton, his surrogates were unsparing.

"I want you to know this, black folks, that you are nobody's firewall," former Ohio State Sen. Nina Turner said, referring to Clinton's so called "firewall" of minority voters. "That we built this country, the sweat and the tears of black folks built this country and we ain't nobody's firewall...You gotta earn our vote."

Turner was one of three speakers Tuesday who had initially supported Clinton, then shifted to back Sanders.

.@ninaturner at Sanders rally taking swipe at Clinton: "We are nobody's firewall!" pic.twitter.com/aKJYiciVNk — Mashable News (@MashableNews) February 17, 2016

Atlanta rapper Killer Mike, also a Sanders supporter, invited something of a firestorm at the event after quoting a woman who said that "a uterus doesn't qualify you to be president of the United States."

Here’s that full @KillerMike riff, where he mentions “uterus” and “being president.” Was quoting someone. pic.twitter.com/kyFJoAeu19 — Juana Summers (@jmsummers) February 17, 2016

Even before Sanders arrived here at Morehouse, Louisiana Rep. Cedric Richmond, a Morehouse alumnus who has endorsed Clinton's campaign, accused Sanders of leaving HBCU students "out in the cold."

In the statement, distributed by Clinton's campaign, Richardson questioned whether Sanders' tuition-free plan would help students at historically black colleges and universities. About half of the nation's HBCUs are not public, Richardson said.

"He owes it to the students to explain why half the HBCUs in the country aren't worth the investment," Richardson said.

Speaking at Morehouse, Sanders said that "we need to provide substantial help to HBCUs that have done a great job educating young African-Americans and others."

While Sanders came out of Iowa with a near-draw and took a decisive victory over rival Clinton in New Hampshire, his path in South Carolina is less certain.

A CNN poll released Tuesday found Clinton with a wide lead over Sanders among black voters, 65% to 28%, in South Carolina. And as the primary has drawn closer, Sanders has been more aggressively courting the black vote.

Earlier Tuesday, Sanders hosted a town-hall meeting at the University of South Carolina in Columbia, flanked by the lawyer for the family of Walter Scott, who was fatally shot by a police officer in South Carolina and Erica Garner, the daughter of Eric Garner, who died in New York in July 2014 after the police used a chokehold to subdue him.

Garner, who also appeared in an ad released by the Sanders campaign last week, told the small, racially mixed crowd, that Sanders was "not afraid to stand against the establishment for the people."

Sanders spoke about his plan to overhaul the criminal justice system, and to make sure that police officers who commit crimes are held accountable.

"I'm tired of seeing videos, videos of Erica's dad and other videos of unarmed people being killed by police officers," Sanders said, adding that "this is not new."

"It has been going on decade, after decade, after decade. The only difference is the cellphone video," Sanders said, at one point holding up his own cell phone. "That’s the only difference because what was going on in the past was never recorded and the police officer’s testimony was accepted as truth. This video, this cellphone, makes all the difference in the world. So clearly as a nation we need criminal justice reform."

Both Sanders and Clinton are aggressively appealing to black voters ahead of the Feb. 27 primary. While Sanders campaigned in Georgia and South Carolina, Clinton gave a civil rights speech in Harlem and announced a $2 billion plan to end the so-called "school to prison" pipeline.

During her speech on Tuesday, Clinton seemed to jab Sanders' recent efforts, saying "you can't start building relationships a few weeks before a vote."

"Race plays a significant role in determining who gets ahead in America and who gets left behind," she said. "Anyone asking for your vote has a responsible to grapple with this reality."