"The darker this world becomes, the brighter our light must shine."

It is Sunday morning at Mother Emanuel Church in Charleston. Pastor Betty Deas Clark is delivering her sermon.

"The darker this world becomes, the brighter our light must shine." Deas Clark repeats the line, saying each word with warm precision.

"Amen" says a man in the congregation. Everyone else is silent.

"The darker the times, the brighter your life needs to be" she adds, more slowly this time.

"Listen!" echoes the man.

After the service Deas Clark retreats to her study downstairs. She is tired. She has been in the job for a month; her family only joined her in Charleston this week.

Her new role is daunting. She takes the place of Clementa Pinckney, a celebrated preacher who was murdered last June just feet away from where she sits now. Eight other members of the church died with him.

There is every reason to speak of dark times. Deas Clark is clear about her task: to "minister to the brokenness of the people."

The white-supremacist massacre at Mother Emanuel was not the only event that brought darkness here in 2015. Two months earlier, just a few miles away in North Charleston, Walter Scott became the latest in America's string of black victims of police violence.

And yet this place did not see unrest like Ferguson or Baltimore. The officer accused of killing Scott was fired and charged with murder. Family members of the Mother Emanuel victims astonished the world by expressing forgiveness for their alleged killer. And the state finally lowered the confederate flag - a symbol of the slavery that built South Carolina.

For African-Americans in South Carolina, this is the backdrop to this year's election. The state plays a prominent role in choosing the president - the first to hold primaries in the South and the first with a racial mix worth speaking of. Twenty-eight percent of the population is black - more than double the national average.

In the aftermath of the killings, "Charleston Strong" became the mantra: This city would pull together rather than fall apart. The media embraced it. But for some, it is highly misleading.

"That narrative is done to create an idea that this is how you handle these attacks against us," says Indeya Assatta. "You pray about it, you hold hands, you forgive."

Assatta is speaking a few blocks away from where Walter Scott died. The activists group Black Lives Matter has its Charleston base here.

Fellow activist Shakem Akhet goes further, seeing North Charleston's payment of $6.5 million compensation to Scott's family as buying silence. "If Walter Scott's mama walked out there right now and said, 'If we don't get justice there's going to be no peace,' I guarantee you, she could cause a riot."

Democrats' territory

There are plenty of other reasons why black South Carolinians might want to riot. According to the most recent figures, African-Americans in the state earn 45 percent less than their white counterparts (in Charleston, almost 60 percent less). For many, home-ownership is out of reach; poor public education contributes to the sense of being in a permanent underclass. Black Republicans are vanishingly rare.

So it is the Democrats who have the run of South Carolina's black electorate, much as they do on the national level. And Hillary Clinton and Bernie Sanders have been fighting for their share. Clinton has long been seen as having the advantage; Sanders, from near all-white Vermont, started out with virtually no black support base at all.

Sanders' vulnerability showed last year when he was upstaged by Black Lives Matter activists at two public appearances, sparking a debate over whether his platform of fighting economic inequality paid enough attention to the specific problems of the black community. He's been trying to compensate ever since, adding positions addressing the "five types of violence" waged against African Americans to his main platform.

It's been a partial success, winning endorsements from prominent figures like film director Spike Lee. But Shakem Akhet is unconvinced, especially by Sanders' attempts to reach out to older civil rights campaigners. "Why are you meeting Al Sharpton? He does not speak for black people today."

'Liars, deceivers and manipulators'

But Akhet's sharpest words are reserved for Clinton, who is counting on black support to help her fend off Sanders' challenge. "Her husband caused one of the most major atrocities in the United States" he says, referring to the 1994 crime bill that contributed to today's mass incarceration of black men. "How can I trust Hillary Clinton? They are liars and deceivers and manipulators."

For Akhet and fellow activist Latisha Imara, nobody running for president today comes close to representing them. "They pat us on the back for two seconds and move on," Imara says.

And the barriers to any candidate who would put racial justice front and center are impossibly high. As Imara puts it, "You cannot reform something that was never made for you."

Akhet, Imara and others like them feel backed into a corner by a system they have no chance of changing. Perhaps little wonder that they look to black nationalism as a possible way out.

"We have to separate from the establishment and build our own," Akhet says. He wants what he calls "cooperative economics" in black communities as a step to what he'd ultimately like to see: an African-American nation.

It's a vision dismissed by mainstream America as cranky, even dangerous. But its persistence in 2016 reflects just how disillusioned many black Americans are. Huge crowds attended a rally by its most prominent advocate, Louis Farrakhan, in Washington last year.

Akhet believes black nationalism is unfairly misunderstood as the violent, even racist vehicle of the angry black man. "You see big old black me walking around talking about black power with a kufi and my Africa sign," he says - and the reaction is, "He's racist!"

Back at Mother Emanuel, such things feel far away. Pastor Betty Deas Clark sees the solution neither in elections nor in revolution. "What we are seeking - equality among individuals - are we seeking it from a political vote?"

But church trustee Leon Amos has some sympathy for the idea of a break from white America. He grew up under segregation; now he sits on the very spot where nine of his friends were massacred by a white man.

"Now we can go into cafeterias, sit down and have something at a lunch counter. But as far as the mindset of people overall, it has not changed a bit."