Washington (CNN) Hillary Clinton has been largely hands off when it comes to Bernie Sanders.

But in an interview with a South Carolina Democrat published Monday, the former secretary of state subtly hit her most threatening primary opponent, previewing how she could go after the senator.

The subtle dig came during a July 23 conversation with Jamie Harrison, chairman of the South Carolina Democratic Party, about how to deal with racism in the United States and, particularly, the Black Lives Matter movement that has captured the attention of activists across the country.

"This (movement) is fueled in large measure by young people and it is a particular development in the civil rights movement that deserves our support," Clinton said. "By that I mean, there are some who say, 'Well racism is a result of economic inequality.' I don't believe that."

The line hits at the main argument pro-Clinton Democrats and Black Lives Matters activists have used against Sanders: The only way he views race issues is through an economic lens.

"I want the next president to feel as strongly that justice is a priority when the epidemic of black people being killed by the police continues," said Rod Morrow, a comedian, podcast host and activist. "To just point to the unemployment as part of the problem with the systemic racism leaves a huge gap."

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The Clinton campaign did not respond to a request for comment.

Last month, after seeing chatter on Twitter that Sanders was talking up his time marching with Martin Luther King Jr., Morrow started mocking the senator with #BernieSoBlack, a hashtag that caught fire as a way for Black Lives Matter activists to knock the presidential candidate.

Indeed, Sanders does regularly frame issues of race and inequality as economic matters, arguing that the key to combating racial disparities is by raising wages and increasing opportunities.

The Vermont senator was confronted by Black Lives Matters protestors when he spoke at Netroots Nation last month. When asked to talk about race in specifics, he responded, "Let me talk about what I want to talk about for a moment."

As protestors heckled him on race, Sanders turned to the economy.

"The issue that we are talking about is that we live in a nation which has wealth and income inequality than any major nation on earth," he said. "And maybe it is time we did something about it."

When one protestor asked him what he would do about race issues, Sanders attempted to shout over the interruption.

"I'll tell you what we are going to do," he said. "We are going to transform the economy in America so that we create millions of decent paying jobs. We are going to make public colleges and universities tuition free. We are going to raise the minimum wage to a living wage. We are going to transform our trade policy. ... That is some of what we are going to do."

Since that event, Sanders has tried to focus more on race, and his aides have acknowledged that the area is blind spot for the senator whose home state is 95% white. The campaign declined to comment for this story, but pointed CNN to Sanders' speech at the National Urban League annual conference in Fort Lauderdale, Florida last week.

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"We need to simultaneously address the structural and institutional racism which exists in this country, while at the same time we vigorously attack the grotesque level of income and wealth inequality which is disproportionately hurting communities of color," Sanders said at the event. "We have to solve both of these problems."

But even during that speech, Sanders argued that "income and wealth inequality" -- above race issues -- are "the great moral issue of our time ... the great economic issue of our time... the greatest social and political issue of our time."

Morrow said Monday that Sanders is learning and even getting better at answering the race question. The problem: His reputation of viewing race issues as economic matter may already be set.

"Sanders has a long way to go with African-American voters," said Bakari Sellers, a CNN contributor and former member of the South Carolina House. "He does get credit for talking about economic inequality but there is much more to it than that."

He said the Black Lives Matter movement is about more than just income inequality.

"I am not sure that Bernie Sanders grasps the gravity of the specific pain that is felt by the black lives matter voter," Sellers said.

During the interview with Harrison, Clinton added that income inequality "is in large measure a symptom of underlying racism and therefore you can't solve this just by creating more jobs, you can't solve this just by getting more kids to go to college."

The comments, though consistent with what Clinton has said about race during the campaign, show the former first lady trying to contrast her message with Sanders.

"They are asking us to face these hard questions and shame on us if we don't do just that," Clinton told Harrison, referring to the Black Lives Matters protestors.

Sanders said late last month that race and economic issues are "parallel problems."

"We have to end institutional racism but we have to deal with the reality that 50% of young black kids are unemployed, that we have massive poverty in America, that we have an unsustainable level of income and wealth inequality," Sanders said. "As Martin Luther King Jr. told us, we have address both."