Susan Page

USA TODAY

ASPEN, Colo. — A leader of the Black Lives Matter movement warns that activists are prepared to protest the platform at the Democratic National Convention in Philadelphia next month, citing the congressional sit-in on the House floor last week over gun control as a possible model.

"There are two things that I'm mindful of: One is that I've not seen a draft or a final version of the platform from the Democratic convention committee, and I think that will have a big bearing on how people mobilize," DeRay Mckesson told Capital Download. "The second is that Congress just sat in, so it'll be interesting to see how the DNC responds to people in protest, given that congressmen literally just sat in and they seemed to validate that."

His comments signal that Republican Donald Trump isn't the only candidate who has to worry about disruptions and demands from within the party at its national convention. While Clinton has the Democratic nomination clinched, rival Bernie Sanders still hasn't formally endorsed her and Mckesson expressed reservations about her commitment to criminal justice and other key issues.

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At 30, he has emerged as a key organizer for the street protests that began almost two years after the police shooting of Michael Brown in Ferguson, Mo. Black Lives Matter staged some protests at campaign events during the primaries, and Mckesson was among the group's leaders who met with Clinton last fall to discuss their concerns.

"I would not say that this is an election that is between the lesser of two evils," he told USA TODAY's weekly video newsmaker series in an interview that took place at the Aspen Ideas Festival, where Mckesson was speaking. "I think that this is an election potentially between a candidate that people are rightfully really concerned about and a candidate that is evil."

The "evil" candidate is Trump, he said, then elaborated on his qualms about Clinton.

"It took a lot of pressure for her to address race —​ like, more pressure than we would think a president in a country where race is such a central topic should take," he said. "So that's like a symbol. I think it bleeds into so many other things. So you think about, what does it mean that you have to sort of fight a nominee to come out with a criminal-justice platform, to come out with a platform about racial inequality, to come out and talk about these things?

"I was at her (campaign) launch in Roosevelt Island, and she talked about, you know, work schedules for working families. It wasn't like she wasn't talking about issues. She just wasn't talking about issues of race."

Mckesson said protests also were likely at the Republican convention in Cleveland. But they could be more consequential at the Democratic convention in Philadelphia because they could resonate with two voter groups crucial to the party's coalition: African-Americans and young people. Clinton has had strong support from black voters in the primaries, but she's struggled to reach Millennials, who overwhelmingly supported Sanders.

At their meeting, Mckesson says he cautioned Clinton directly that she couldn't count on antipathy to Trump to turn out black voters.

"I said, 'Hillary, I worry that you are underestimating how many people plan to sit this out because they are disillusioned,'" he said. "And if the DNC (Democratic National Committee) and if Hillary's camp don't help people see her as a real choice, despite their misgivings about her, I think this will be more of an uphill battle than it already is."

If the Democratic platform doesn't endorse a $15-an-hour minimum wage, strong criminal-justice provisions and community oversight of police departments, "I think that you will see protests around the issues," he said. He credits Clinton with proposals to address the wealth gap between whites and minorities and to increase funding for civil-rights enforcement by the Justice Department. But he said activists also would be looking for increased powers for the Justice Department and attention to issues such as civil-asset forfeiture -- provisions that allow law-enforcement agencies to seize and keep property they say was involved in a crime.

He also indicated that Black Lives Matter intended to keep pressure on Clinton if she is elected president.

"What's real about Hillary is she will not be able to govern without a coalition of people of color," he said. "She won't be able to get elected without black people or Latinos. She won't be able to govern without them. It is unfortunate that it took so much pressure for the platform to be responsive to those communities."

That means "we'll need to organize no matter who the next president is," he added. "We have an incredible opportunity to hold the next president accountable, especially if it's Hillary, because she can't govern alone."