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South Carolina is a solidly red state. It's also critically important to Democrats running for president. Its large African-American voting bloc makes it a key state for those trying to capture the party nomination. So many candidates are already spending time in the state trying to endear themselves to those voters. NPR's Scott Detrow has been on the road there with New Jersey Senator Cory Booker.
SCOTT DETROW, BYLINE: It's Sunday in rural South Carolina, and Cory Booker sounds like he's preaching.
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CORY BOOKER: You cannot love your country unless you love your fellow countrymen and women. You may not always agree with them...
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DETROW: Booker's not making a campaign stop in a church. He's in a high school cafeteria telling a couple hundred voters why he's centering his presidential campaign around the idea that Americans need to come together and treat each other with more love and empathy.
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BOOKER: I'm - I have great ideas, some of which I've gotten into law, some of which I implemented in Newark. But when are we going to see that the cancer on the soul of our country is the divisions that exist between us in a nation that's united, that claims to be one nation under God? Well, we need to put the indivisible back into that one nation under God.
DETROW: That's despite the fact that so many Democratic voters are so angry at President Trump.
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BOOKER: You're one of those people who wants to fight fire with fire. Now, I ran a fire department. I was a mayor. I oversaw - I appointed the guy that really ran it. Let's not exaggerate. But that's not a good strategy to put out fires in a home, is to fight fire with fire. They brought water.
DETROW: South Carolina has been an important early primary state for decades. This time, though, most Democratic campaigns see it as even more important. That's for two key reasons.
First, the party has become increasingly focused on and energized by diversity. And South Carolina is the first primary state with a significant African-American population. Second, the calendar - as longtime South Carolina political operative Jaime Harrison points out, South Carolina will vote just days before Super Tuesday, where several big Southern states with a lot of black voters will head to the polls all at once.
JAIME HARRISON: Really, you know, South Carolina becomes the gate to the rest of the South and other states with similar demographics.
DETROW: Do well there, and suddenly you could be the leader. The 2020 Democratic field is the first ever to include two black candidates among the frontrunners. And both Booker and California Senator Kamala Harris haven't been shy about talking a lot about race. Here's Harris this week on the syndicated radio show The Breakfast Club.
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KAMALA HARRIS: Guess what the Russians have made very clear if - if we weren't before? That the issue of race is America's Achilles heel. And it has now become an issue that is not only about civil rights, but also an issue that is about national security.
DETROW: Harris was referring to the fact that Russian operatives tried to exploit racial fault lines in their 2016 disinformation efforts. In South Carolina this weekend, all three crowds at Booker's events were predominantly African-American. But many voters were like Beverly Dianne Frierson, who said she's not going to be voting based on race alone.
BEVERLY DIANNE FRIERSON: I think it's great that we have Cory and Kamala. However, I also think that it's really great for the Democratic Party that we have a tremendous group of people who are very, very intelligent, highly skilled.
DETROW: Besides, Frierson said...
FRIERSON: I think it's much, much too early to say I'm for X, Y or Z. I want to attend as many rallies for the various candidates as possible, listen and learn.
DETROW: And it's clear Booker wants to take as much time to do that as possible. Several of his events stretched past the two-hour mark, and afterwards he waited as long as it took to make sure every single voter who wanted to could say hello, pose for a selfie or even get Booker to record videos on their phones to send to their families or friends.
Scott Detrow, NPR News, Sumter S.C.
(SOUNDBITE OF THEO CROKER'S "REALIZE") Transcript provided by NPR, Copyright NPR.