The latest CBS News poll shows Donald Trump leading his closest rival in South Carolina, Ted Cruz, better than two to one.
On the Democratic side, Hillary Clinton leads Bernie Sanders by 19 points as both of them court African Americans.
As Sanders met with ministers in Columbia, South Carolina, Clinton sat down with Civil Rights leaders in Harlem.
Both of them trying to send the same message.
"My campaign is really about breaking every barrier," Clinton said.
On Tuesday, Clinton proposed a $2 billion plan to reform school discipline policies that she said are failing black students.
"We will dramatically expand support for guidance counselors, school psychologists, and social workers," she said.
Sanders focused on black incarceration rates.
"Tell me why in the richest country in the history of the world why should we have more people in jail than any other country on Earth? Anyone want to tell me why?" he said.
Clinton is leading among South Carolina African Americans by nearly 40 points.
She sought to cement that advantage on Tuesday, implying Sanders is new to the fight for racial equality.
"You can't show up at election time and say the right things and think that's enough," Clinton said. "We can't start building relationships a few weeks before a vote."
He argued the Civil Rights movement inspired his fight against Wall Street greed.
"People didn't cower," Sanders said. "People did not back down. People kept going forward. That, my friends is courage."
Both candidates bring up race more frequently than then-Senator Obama did in 2008 -- perhaps because he was all too aware of the biases that Clinton and Sanders are highlighting now.