Former secretary of state Hillary Clinton after winning the Democratic Nevada Caucus.(Melina Mara/The Washington Post). Sen. Bernie Sanders (I-Vt.) at the Henderson Pavilion in Henderson, Nev. (Ricky Carioti/The Washington Post)

Voters head to the polls Saturday for the South Carolina Democratic primary, giving us our first indication of how a heavily black electorate will decide in the race between Hillary Clinton and Bernie Sanders.

We pretty much know who will win black voters and the state (Clinton by a lot, and Clinton by a substantial amount, respectively), but the closeness of the race and the black vote matter deeply. How else to explain the candidates’ almost-singular focus on black voters in recent weeks?

Young black voters represent an important constituency to Democratic presidential candidates. Growing support for Bernie Sanders has left many older voters, who favor Hillary Clinton, questioning the political judgement of the younger generation. (Dalton Bennett/The Washington Post)

Clinton is clearly leading among black voters — so much so that states with heavy black populations have been called her “firewall,” but Sanders isn’t without some helpful recent headlines. Let’s recap the many big names who have weighed in here.

For instance: Spike Lee and Michelle Alexander have said plainly that Clinton does not deserve the black vote. Lee, the filmmaker behind the prodigious and prescient “Do The Right Thing” and more recently the less consequential, “Chi-Raq,” taped a radio ad for Sanders. And Alexander, the author of “The New Jim Crow,” a book that delivered new and bipartisan life to the fight for criminal justice reforms, out and out wrote in a piece for the Nation stating that black people should not vote for Clinton because of Clinton’s history backing polices that actively and deeply harmed black America.

That sentiment bubbled to the top this week, when a protester got Clinton to concede that she shouldn’t, in 1996, have referred to “super-predators” while discussing then-President Bill Clinton’s criminal justice reforms.

Ben Jealous, the former head of the NAACP credited with resuscitating the centenarian organization’s interest in post-1965 civil rights challenges, has said and written much the same as Alexander. And both Jealous and the long politically outspoken artist Michael Render, a rapper also known as Killer Mike, have not only endorsed Sanders but also hit the campaign trail on Sanders’s behalf. Sanders even made a sojourn to meet with one Rev. Al Sharpton in Harlem — a place that may be the symbolic center of black life in the United States even if, due to gentrification, it is no longer majority black.

At the same time, these are largely the exceptions. A host of well-known, influential and well-connected black elected officials and leaders of civic and religious institutions have made their support for Clinton quite clear. And they have done everything possible to identify themselves as people opposed to a Sanders candidacy. Clinton has also claimed most of the official endorsements of what we’ll call the “black and grieving” lobby — a tragically full cornucopia of black Americans, most of them women, who have lost family members to alleged police misconduct, violence wrought by the United States’ ever-growing supply of easily accessible guns, or some combination of the two.

Rep. John Lewis (D-Ga.), the youngest American to address the massive crowd at the 1963 March on Washington and former leader of the Student Nonviolent Coordinating Committee, told a reporter asking about Sanders’s frequent references to his mid-20th-century civil rights activism that he never met Sanders. And, as there were not hundreds of thousands of people in the District that weekend, Lewis also said he never saw Sanders at the March on Washington.

And Rep. Hakeem Jeffries (D-N.Y.), the Congressional Black Caucus whip, told reporters that Sanders has spent most of his congressional career ignoring or avoiding policy issues of grave concern to black Americans. Clinton, Jeffries said, by comparison has been a long-time and committed “true friend” to black America’s policy needs.

And, almost as if to say that the shooting death of an unarmed black person is the modern uber-black experience, the Clinton campaign has collected endorsements from several grieving black relatives. The mother of Trayvon Martin has even stumped for Clinton and explained her pro-Clinton voting rather logically in some detail.

Finally, Clinton has brought some Hollywood help to South Carolina. We are talking about the actresses Angela Bassett, Vivica Fox and Uzo Aduba, and television producer Shonda Rhimes, here.

Sybrina Fulton, the mother of Trayvon Martin, endorsed Democratic presidential candidate Hillary Clinton during a town hall meeting at Central Baptist Church in Columbia, S.C. Trayvon Martin, who was unarmed, was killed by a neighborhood watchman George Zimmerman in Florida. (Reuters)

Both Sanders and Clinton have visited more than a few black churches and done the whole shake-hands, kiss-babies, clap-and-sway-to-the-sweet-gospel-music thing. We could go on. We really could. The writers on the Larry Wilmore show indicated that what Clinton and Sanders have done to try to secure black votes has helped to create one of the “blackest Black History months ever.”

Which is actually a pretty good point. South Carolina has, of course, held a prominent presidential primary for years, but this campaign has been different when it comes to overt appeals for the black vote.

In South Carolina, black voters comprise the majority of the Democratic Party’s electorate, about 55 percent. So their thoughts, their sentiments and their priorities rule. And, it offers both the Clinton campaign — which leads with non-white Democratic leaning voters — and the Sanders camp more than an opportunity to perfect the ribbon-cutting functions of stumping for black votes. What’s happening in and around the South Carolina Democratic primary and the racially and ethnically diverse Super Tuesday states beyond it is actually quite important.

For the first time in what may be, well, ever, there is a genuine competition for the black vote — a critical and now very much proven portion of any winning Democrat’s coalition.

For now, the ultimate outcome of all this activity is not yet clear and won’t be until Saturday or perhaps even Tuesday. There is some indication that Clinton's endorsements and policy positions have given her the large overall lead with black voters, but one which is strongest among those age 40 and older. In contrast, Sanders appears to be narrowing the still-sizable gap with black voters under age 40. There's actually something quite similar happening with older and younger white Democrats too.

The problem for Sanders is he has far less young black support than young white support significant problems with older black voters, too.

See what we mean? This is a more complex black voter chase — one where a variety of experiences matter. And, it’s one you can expect to see played out in where Clinton and Sanders each opt to spend their time and put in those last bits of ceremonial and substantive effort Saturday as South Carolina Democrats go to the polls.

We won’t overstate things: This competition has, thus far, only amounted to Clinton framing issues such as child care and the gender wage gap, voting rights and criminal justice and gun policy reforms in ways that make their importance to black voters clear. They are all, of course, issues that aren’t exactly that far outside Clinton or any other Democrat’s wheelhouse.

And, Sanders — a self-identified democratic socialist — stuck so long to his aggressively race-neutral but certainly class-conscious calls for reducing economic inequality that many political reporters routinely refer to him as a one issue candidate.

Because issues of economic inequality do, indeed, affect black America more severely than other segments of the population, there was something for black voters in Sanders’s message from the beginning. Sanders does, after all, want a $15 federal minimum wage, compared with Clinton’s call for $12. But women of color make up a disproportionate share of those earning minimum wage, and Clinton has said bluntly for some time that her fight on this issue is for these women, while Sanders and his mostly white supporters were still insisting that nothing more than economic inequality requires the nation's attention.

More recently, Sanders has added his own set of criminal justice reforms and a lot of hard talk and tactical action highlighting the role Hillary Clinton played in making mass incarceration in the United States far worse. He has become a single-issue-plus kind of candidate.

All told, Democrats are still offering a list of specific policy positions and promises to black voters far smaller and perhaps lamentably narrower than what they do and say in pursuit of white votes. But at least the competition is real.

Understand, though, that this conclusion isn’t some kind of subtle critique aimed at President Obama and his 2008 or 2012 campaigns. Obama, like Sanders, scrupulously and sometimes insistently avoided race-specific policy promises, too, but delivered some things in office that have been particularly good for black Americans and others with limited income such as the Affordable Care Act.

There have been volumes written about the pragmatism of Obama’s race-neutral approach. There are heads that would explode if Obama said anything he would like to do would be particularly good for black Americans. But just because Obama and other political figures haven’t spoken that way does not mean that patterns do not exist in terms of who benefits most from policy reforms.

What we are saying is that, probably through some combination of full inside-the-party knowledge of the critical role that black voters — particularly black women — played in making two Obama terms possible and a far more intense and left-leaning competition for the Democratic nomination than Clinton probably ever expected from Sanders has forced specific policy commitments on a small set of issues among many of concern to black Americans. Sanders’s struggle with this demographic, in particular, have made clear how vital it is.

And there’s pressure on both candidates now to clearly do more, say more and go further. After all, following Saturday and Super Tuesday, the candidates head to Flint, Mich., next week for a candidates debate.