Much has, will and perhaps must be written about the irony of South Carolina Democrats delivering to Hillary Clinton in 2016 her first resounding early-state primary victory. It was, after all, just eight years ago that these same South Carolina voters answered the 2008 Clinton campaign's argument that she was the pragmatic and therefore best option with a similarly resounding defeat.

Indeed, in 2016, South Carolina has reversed course, and this time it turned toward what most observers will describe as the path of political pragmatism, giving Clinton a nearly 50-point victory over Bernie Sanders.

But there is another story, one that hides in plain sight but may well be ignored. Look closely at the exit poll data, and the indicators of a massive win for Clinton. There is evidence of substantial but far from record-setting overall primary turnout there, too. But, there is also this: Black voters turned out and voted in large numbers relative to other Democrats, giving their numerical majority within the party added meaning.

Hillary Clinton won the South Carolina Democratic primary on Feb. 27. Here's how. (Peter Stevenson/The Washington Post)

Black voters in South Carolina cast 6 in every 10 Democratic primary votes, according to CNN's exit poll data. That ratio is huge — and sets a record-high in South Carolina black voter participation rate. The previous high was 55 percent, set in 2008, when the first black president was on his way to being elected. And if so, what we have here is solid evidence of not one but at least two cultural and political changes that the Obama years have wrought.

First, this is what Democratic voter turnout looks like — these are its outcomes when black voters are convinced of their ability and authority to fundamentally shape American democracy. It is a result that should begin to crush the popular and often repeated myth that black political behavior in 2008 and 2012 was nothing more than a blip, a fleeting kind of emotion-only engagement inspired by a singular and history-making black candidate.

Obama's 2008 South Carolina primary win and later election as president affirmed that when active and engaged and in solid coalition with other non-white voters and progressive whites who share priorities, demographic shifts in the country's population can translate to political dominance. Saturday's South Carolina primary results indicate how essential each element of the so-called "Obama Coalition" remains for any successful Democrat.

Second, the South Carolina result challenges almost directly the rather standard and presumptive claim that the party, which is home to the most racially and ethnically diverse array of voters, must leave the earliest and most influential choice about its presidential candidate to two states that look very little like the party or the country. The argument that voters in Iowa and New Hampshire are somehow specially trained or primed and therefore "take the responsibility seriously," in some sort of unique way, seems largely emotional, even nostalgia-driven in the light of turnout results in far more diverse South Carolina.

If the turnout patterns and election outcomes look the same in most Super Tuesday states, consider that another blow. Voters in New Hampshire and Iowa didn't simply behave quite differently than those in Nevada and South Carolina; they delivered different election outcomes indicating that, for them, Sanders's message and Sanders's political priorities were a good or at least not an uncomfortable fit.

To put it bluntly, in Iowa, Sanders's race-neutral message centered around a kind of economic inequality where a dastardly 1 percent (no race mentioned) fares well at the expense of the 99 percent (no race mentioned), thus creating unjust and untenable conditions that are the same in all the 99 percent's lives has some obvious appeal to liberal voters. It is also a message that allowed Clinton a narrow win in Iowa, a blowout loss in New Hampshire, a larger but not resounding victory in more diverse Nevada and a massive win in South Carolina.

You see, there are reasons why this remains most appealing to young, white, liberal voters. For them, a race- and gender-neutral policy platform is most likely to seem sufficient to improve all Americans' lives.

But other voters — those of color — may not be so readily convinced. To them, the limits of race-neutral policy, even when shaped, formed and influenced by a black president, have been made plain during the Obama years.

Remember how often in the early years Obama used the phrase "a rising tide lifts all boats," or insisted that he intended to serve as all of America's president. The president had little choice, as has been said and written many times. He could not give lethal ammunition to his political enemies or those who are politically paranoid.

Now, at the end of the Obama era, some things are indeed quantifiably better for black America — health insurance coverage rates, unemployment, household income and wealth — than at the beginning. But by most of those measures of social and economic well-being, most of white America has recovered and left the hospital. Most black and Latino Americans remain under close observation. Some are in stable condition, but a disproportionate share remain in the ICU.

Clinton, as we have noted before, engaged in all the standard fare of black-voter stumping in 2016. She went to churches. She was seen at soul food restaurants. She collected public support and endorsements from black elected officials and other recognized names. But she also did something else.

The Clinton campaign has stuck, just as her critics charge, to a rather safe, barely left-of-center, utterly non-radical list of reform priorities. That's true. It really is. But in her stump and issue-specific speeches, Clinton has referred to ways by which issues, such as Voter ID laws, gun violence, criminal justice reform, gender wage imbalances and the long unchanged minimum wage, directly and even more deeply shape and distort the lives of black and Latino Americans. The natural conclusion of that discussion is: 'Here is what my policy will do for all of us, and here is what it will do for those Americans who yes, actually or disproportionately have it worse.'

Voters have to decide whether or not to believe her. But that is what she has said. Voters don't have to like explicit talk about race and ethnicity. But it is undeniable that, for quite some time, this was a major difference between the Clinton and Sanders campaigns.

Of course, it is true that Clinton arrived in South Carolina with some undeniable political advantages — name recognition, a beloved former president for a husband, and more campaign and outside money than any other candidate on either side of the race. But it is also true that, over the course of the 2016 election, every one of those factors have proven subservient to this: The relationship between a candidate, their policy ideas or promises and what voters believe they really need.

Demographics are not destiny. They must be paired with political engagement and action —voting, at the very least — to deliver real influence and political say.

What South Carolina's black voters — who comprise more than half of Democrats in that state and, as CNN's early exit poll data indicates, 61 percent of those who cast ballots in that state's primary — said on Saturday is that they completely and totally get that.

The question for Sanders, his supporters, and those who wish to see his campaign continue is: What do the changing demographics of America, of the Democratic Party, and a large number of voters of color expecting their experiences and priorities to share center stage, now mean that he must do differently.