Just eight years ago, Democrats were treading lightly on the issue of race in America. Although he would become the first black president in the history of the country, Barack Obama himself tried to avoid the issue — addressing it mostly when high-profile news events forced his hand, like his pastor's comments on race and the death of Trayvon Martin during his presidency.

Today, the issue is front and center of the Democratic presidential primary elections. It has come up at every single Democratic debate. It has been raised by the candidates even when they're asked about issues unrelated to race.

Just look at this answer from Bernie Sanders, when asked about the racial disparities in the criminal justice system at a Democratic debate in February:

This is one of the great tragedies in our country today. And we can no longer continue to sweep it under the rug. It has to be dealt with. Today, a male African-American baby born today stands a one-in-four chance of ending up in jail. That is beyond unspeakable. So what we have to do is the radical reform of a broken criminal justice system. What we have to do is end over-policing in African-American neighborhoods. The reality is that both the African-American community and the white community do marijuana at about equal rates. The reality is four times as many blacks get arrested for marijuana. Truth is that far more blacks get stopped for traffic violations. The truth is that sentencing for blacks is higher than for whites. We need fundamental police reform, clearly, clearly, when we talk about a criminal justice system. I would hope that we could all agree that we are sick and tired of seeing videos on television of unarmed people, often African-Americans, shot by police officers. What we have got to do is make it clear that any police officer who breaks the law will, in fact, be held accountable.

This is an incredibly strong answer for anyone interested in racial justice. It hits on the three big issues: mass incarceration, the war on drugs, and policing. And it ties all three issues to race.

It's a remarkable shift that shows the success of the Black Lives Matter movement. But it also reveals the big chasm between Democrats and Republicans on this issue: While Democrats engage with this issue in debates, Republicans have by and large avoided it or, in some candidates' cases, acted in ways that show they are for continuing a status quo that puts much of the country's power in white hands.

The big chasm between Republicans and Democrats on racial justice

Perhaps no moment captures the Democrats' willingness to talk about racial justice issues than Hillary Clinton's closing comments at the January 17 debate. Clinton was asked to make a closing statement. She could make any statement. And she brought up race — specifically, how it may have impacted the Michigan government's response to the lead crisis in Flint.

Clinton said:

I spent a lot of time last week being outraged by what's happening in Flint, Michigan, and I think every single American should be outraged. We've had a city in the United States of America where the population, which is poor in many ways and majority African American, has been bathing and drinking in lead-contaminated water. And the governor of that state acted as though he didn't really care. He had requests for help that he basically stonewalled. I'll tell you what: If the kids in a rich suburb of Detroit had been drinking contaminated water and being bathed in it, there would've been action.

This is simply remarkable. Clinton had a chance to give any vague campaign platitude as her closing statement, but she chose to call out what could be an example of how race and white supremacy still influence modern American politics and policies.

It's notable enough that Clinton, the supposed establishment candidate, brought up the issue by her own will. But the other candidates have too — Sanders, for example, effectively repeated her comments on Flint nearly verbatim at the February 4 debate.

What about the other side? Republicans have barely discussed racial justice. In their debates, they have spent at best a few minutes on them. Rand Paul, now gone from the race, was the only candidate who seemed willing to seriously bring them up. Other candidates at best gave vague, quick answers and nothing else.

In fact, if anything, Republicans have been talking in the direction of supporting white supremacy with coded language against Hispanic and Muslim Americans.

Donald Trump, the frontrunner in the Republican race, is racist and xenophobic. He launched his campaign by characterizing Mexican immigrants as rapists and criminals. He called for banning all Muslims from entering the US. He talked favorably about putting Japanese Americans in internment camps during World War II. And so on.

Yet Trump is the leading Republican candidate. He is leading national polls. He is leading in South Carolina and Nevada, the next two states to vote. He came second in the Iowa caucuses, and he won New Hampshire's primary election.

Sanders on February 10 explained this divide between Democrats and Republicans in an interview with Stephen Colbert:

I think a lot of Donald Trump's supporters are angry. They're in many cases people who are working longer hours for low wages. They're people who are really worried about what's going to happen to their kids.… People have a right to be angry. But what we need to be is rational in figuring out how we address the problems and not simply scapegoating minorities.

Trump by no means represents all Republicans. (There are two Hispanic candidates on the Republican side, after all.) But clearly, a lot of GOP voters support him. And while other candidates have called him out on his gross comments, they have also used much of the same rhetoric on Muslims.

So Republicans are either comfortable with apathy toward racial justice and equality or they're willing to talk in a way that actually props up the idea of white supremacy. Democrats, meanwhile, are not shying away from at least speaking openly about achieving racial equality.

The big reason for this divide: Black Lives Matter.

The Black Lives Matter movement has repeatedly forced Democrats to talk about racial justice

Very early in the Democratic race, it wasn't clear if criminal justice issues would play a major role. Besides Clinton, whose first big campaign speech hit on criminal justice and race, the candidates didn't seem to talk about racial justice much.

This changed quickly: Pretty soon, Black Lives Matter protesters began showing up at rallies for Sanders and former candidate Martin O'Malley and demanding that the candidates talk about these issues. So the candidates released racial justice platforms.

But the Democratic candidates weren't just responding to some heckling at rallies — they were also responding to a clear shift in American politics, one that's visible in the polls.

A 2015 survey from Gallup, for example, found that Americans are more likely to say black people are unfairly treated in all aspects of society, including police encounters. And a survey from the Pew Research Center found a 20-year high in Americans saying racism is a "big problem."

But these general findings don't show the partisan divide on this issue. When divided by party, Pew found 61 percent of Democrats, including 61 percent of self-identified conservative and moderate Democrats, said racism is a big problem. By contrast, 41 percent of Republicans said it's a big problem — a 20-point gap. (One caveat: Many white Americans, which make up the great majority of the Republican Party, say racism against white people is worse than bias against black people.)

Looking at these polls, it's hard to think of anything besides Black Lives Matter and the media coverage surrounding it — of mass incarceration, police use of force, and so on — that drove the shift. And Democrats, seeing the interest in their base, have gone to great lengths to capture that shift in their campaigns, especially as they strive to win black voters in upcoming primary elections.

Why Democrats need to talk about racial justice

The broader context here is not just that Democrats are paying attention to a growing issue in their coalition of voters, but that Democrats are finally participating in a long-running conversation that has been left to the right for years.

As white supremacy and systemic racism lost support among much of the public, the Republican Party and conservatives did not simply drop the issues and move on. They instead adopted dog whistles and coded language that continue in much of public dialogue in America today. It was a crucial part of Republicans' Southern strategy following the 1960s — by invoking many white Americans' racial resentments, GOP presidential candidates successfully secured states in the South that historically went Democrat.

Ian Haney-López, author of Dog Whistle Politics: How Coded Racial Appeals Have Reinvented Racism and Wrecked the Middle Class, recently laid out how this worked.

"The 20th century witnessed a strong push to get beyond white supremacy, to get beyond a social commitment to ideas that elevate whites as human and decent and worthy and nonwhites as less than human and dangerous and unworthy of concern," Haney-López told me. "That push has been most successful at a formal level, but what you see in response sort of as an evolution is the search for proxy language that allows you to express the same fears in ways that aren't formally offensive."

Today, many conversations about policy on the right are rooted in this kind of racial anxiety. With criminal justice and public safety, many white people hold implicit (and sometimes explicit) biases against black people, often characterizing black men in particular as criminals. With immigration, there are fears about Hispanic and especially Mexican immigrants changing the makeup of America. With national security, much of the conversation is really an expression of Islamophobia.

The rise of Trump demonstrates this: Many Republican voters back a platform that is racist, nativist, and xenophobic. It explicitly supports banning a whole group of people from the US. And Trump supporters back their candidate proudly, despite attempts by elites in the party to take down Trump.

Democrats basically let this kind of conversation and language persist on the right without much interference for decades. It dominated the US's criminal justice conversation for much of the 1980s and 1990s — Clinton herself talked about "superpredators," a word that has been repeatedly used by politicians used to invoke white Americans' fear of black crime.

This type of language had serious consequences: It's one of the reasons that tough-on-crime measures, the drug war, and mass incarceration have been allowed to go on for so long, despite warnings from black leaders that this was having a horrific impact on minority communities.

"Almost every conversation on the right has as a subtext an indication of race," Haney-López said. "On the left, we've got this move that says we shouldn't talk about race, because race is divisive, so let's just focus on economics. It's a disaster, because we're not responding to the racial narrative, so we're not responding to white people's genuine racial fears. At the same time, we're not really addressing the genuine racial justice issues confronting communities of color, which is part of what the Black Lives Matter movement is trying to do."

The Democratic presidential campaigns and debates show that this is changing. It's potentially a very big moment in American politics.