Following a decisive victory in New Hampshire, Democratic presidential candidate Bernie Sanders is heading to Morehouse College next week to shore up support from young African-American voters.

But the U.S. senator from Vermont will be countered by a heavy-hitting Hillary Clinton surrogate: U.S. Rep. John Lewis, a civil rights icon.

Clinton is bringing the Atlanta Democrat to the political foreground in South Carolina and Georgia just as Sanders is trying to establish a presence in the South and make inroads with blacks. The message: We have it locked down.

Clinton currently has a nearly 30-point lead over Sanders in South Carolina, but her supporters are still hoping that bringing in her longtime friend and an alum of the Southern Freedom Rides, lunch counter sit-ins and March on Washington could help build a sense of momentum following disappointing finishes in Iowa and New Hampshire.

“Atlanta is the cradle of the civil rights movement, and John Lewis’ prominence as our top elected official in seniority and Democratic politics in Georgia carries tremendous weight and credibility,” said Georgia Democratic Party Chairman DuBose Porter, a Clinton supporter. “People trust John Lewis because he’s spent his life in the trenches. He’s brought a lot of people up in his journey with him, and certainly Hillary Clinton is one of those who have been on this journey with him.”

Lewis, who endorsed Clinton in the fall, is considered one of the most influential Democrats in the state and in Congress, and colleagues say his voice has weight.

“It’s tremendous,” U.S. Rep. David Scott, D-Atlanta, said of having Lewis in your political corner. “John Lewis is a legend. He has been on the forefront of the battle for voting rights and civil rights since 1960, and certainly his voice means an awful, awful lot.”

Lewis on Thursday referred to his work during the civil rights era while offering a full-throated endorsement of Clinton during a press conference members of the Congressional Black Caucus political action committee held to back the former secretary of state. At the same event, he dismissed Sanders’ civil rights work as a University of Chicago student in the 1960s.

“I never saw him. I never met him,” he said of Sanders. “I chaired the Student Nonviolent Coordinating Committee for three years from 1963 to 1966. I was involved in the sit-ins, the Freedom Rides, the March on Washington, the march from Selma to Montgomery and directed the voter education project for six years. I met Hillary Clinton, I met President (Bill) Clinton.”

Lewis’ office did not respond to requests for comment later Thursday.

Shoring up support among her base, which includes African-Americans and Latinos, is central to Clinton’s post-New Hampshire strategy, one that could pay off tremendously, since minorities make up a larger slice of the electorate in the South than in the first two nominating states. In her concession speech in the Granite State on Tuesday, Clinton focused her message on racial justice issues, including criminal justice and immigration.

Sanders, meanwhile, is lagging in endorsements from prominent black leaders, and he has also spent very little time, so far, campaigning in the South.

“Since African-Americans probably cast 60 percent of the votes in the Democratic primary, something like that, it would be very helpful for Sanders to have some credible leadership in that community,” said Charles Bullock, a political science professor at the University of Georgia. “He doesn’t seem to have anything in place here.”

Emory University’s Andra Gillespie, who focuses on African-American politics, said Lewis’ endorsement could have a particular impact on older, more centrist Democrats who may still be undecided.

“Lewis’ endorsement will carry greater weight among people who are older and people who might be liberal, but either you could call it more pragmatic or fiscally conservative. Clinton is hoping to capitalize on that generally, hoping that culturally Sanders’ rhetoric doesn’t resonate well in Southern audiences,” Gillespie said.

Lewis has been a longtime Clinton supporter, but the pair hit a major road bump in 2008, when Lewis abandoned her to support the candidacy of Barack Obama. Lewis had initially endorsed Clinton and supported her in Georgia’s Democratic primary, but after his district overwhelmingly broke for Obama, the congressman said he felt compelled to switch.

But it seems that their relationship has now recovered.

“John Lewis is an American hero who has fought for justice and equality throughout his entire life,” LaDavia Drane, the director of African-American outreach for Hillary for America, said in a statement, “and that’s why Hillary Clinton could not be prouder to have his support.”