When pundits discuss the Democratic presidential primary in South Carolina, they usually focus on one issue: Who will black voters support? It’s an important question; African Americans are a critical part of the Democratic coalition, yet they are mostly absent from the primary season’s first Democratic contests in Iowa, where 2016 Democratic caucus participants were 91 percent white and 3 percent black, and New Hampshire, where they were 93 percent white and 2 percent black. South Carolina, whose 2016 Democratic primary electorate was 61 percent black and 35 percent white, is the first state in which black voters will flex the muscles that have been key to electing Democratic presidents for a long time.

Still, white Democrats are a force in South Carolina; 35 percent is not nothing. It seems obvious, if not often discussed, that the strongest candidate will be the one who can pull the highest number of votes from both groups.

So when a line of more than 1,000 people, the large majority of them white, snaked through the Myrtle Beach Convention Center at midday Monday, all waiting to see Kamala Harris, the only black woman in the race, it said something about the California senator’s appeal — especially after Harris earlier drew strong crowds in heavily black areas of the state.

Harris has been on a roll after the first Democratic debate on June 27. In the debate’s most-discussed face-off, she went straight after front-runner Joe Biden over the issue — who would have predicted? — of busing in the 1970s. To some moderates and Republicans, Harris’s attack made little sense — Biden was clearly right — and she partially backed away from her position later. But a lot of Democrats liked the fact that she boldly took it to the leader, leaving Biden sputtering and confused.

A CNN poll taken shortly after the debate showed Biden dropping 10 points, with Harris rising nine. A Quinnipiac poll taken at the same time showed an even more dramatic change among black voters: Biden down 17 points and Harris up 16. In Myrtle Beach, Harris was still riding the wave. Voters white and black were smitten.

“I love her intelligence, her courage, her articulation, her experience, her grasp of policy,” said Lisa Hinkson, who is white and from nearby Pawleys Island. “I love her composure — all those things appeal to me greatly about her. She’s awe-inspiring.”

“You can just put ditto,” said Hinkson’s friend Joe DiLorenzo, of Carolina Forest.

“She was dynamic, and I like her vision,” said Ray Smith, who is black, from Murrells Inlet.

Is he considering any other candidate?

“Not at this point,” Smith answered. “I’m pledging all my support to her.”

“Same thing,” said Smith’s wife, Kathy. “I’m all for her.”

In Myrtle Beach, voters of all types worried about Biden’s age. In a talk after Harris left the stage, Chad Horton and Leslie and Willie Byrd, who are black and from Myrtle Beach, said they like Harris but have not fully decided on a candidate yet. In any event, they had real concerns about Biden.

“Honestly, I don’t think he’s going to stay in the lead,” said Horton.

“I don’t think so either,” said Leslie Byrd. “I think he’s dropping off. He’s losing momentum right now.”

“He’s getting slow,” added Horton. “He can’t think that quick, on the go. He gets shaken. I don’t think he could beat Trump on stage in a real debate. I think Trump would just tear him up.”

Harris’s platform, of course, is pure woke progressivism. Much of the crowd was with her. But there were at least a few people looking for a bit of moderation. The first question when Harris finished speaking came from a man who wanted “Medicare for all” but worried about the dislocations caused by moving to a new system too quickly. He wanted to see preliminary steps, such as lowering the Medicare eligibility age to 55. Harris was conciliatory and appeared to satisfy him when she said, “It can’t just happen overnight — there will be a transition period.”

Later, a woman asked about immigration in a way that sent Harris into a revealing monologue.

“My name is Joanne, and I really, really want to beat Trump,” the woman began.

“Me too,” said Harris.

“I’m concerned that the Democrats are only focusing on the humanitarian problems at the border and are not putting forth policies that control or reduce the flow of immigrants from the Northern Triangle,” Joanne said. “How would you address President Trump when he claims the Democrats are for open borders?”

Harris began by ignoring the question. She talked about separating children from their parents. About people fleeing “murder capitals of the world” to come to the United States. About why a mother would would bring her child on a dangerous journey to this country. About the detention center she had recently visited in Homestead, Florida. “Stop the human rights abuses, and shut down these private detention facilities,” Harris declared forcefully.

Of course, that was not the question.

“Now, on the issue of border security,” Harris continued. “We have to enforce our laws and keep our border safe. It is part of what this president is trying to do to really misinform the American people to say that Democrats don’t care about border security. I can speak for myself: I am absolutely in favor of border security. We have to, any nation has to be concerned with that, and we of course do.”

It is still too early to see a definitive pattern in South Carolina. Back in 2007 and 2008, Hillary Clinton was leading in the Democratic primary race here, but when black voters realized Barack Obama was the real deal, not a protest or show horse candidate, they flocked to support him. Obama blew past Clinton in the Democratic primary on the strength of overwhelming black support, but he also won about 25% of white votes in a three-way race with Clinton and John Edwards.

That could, perhaps, be a model for Harris, in the Obama role, and Biden, in the Clinton role. “Hillary was popular early in 2008, but Obama devastated her in the last month,” said David Woodard. “Now, the old Hillary Clinton base of liberals who don’t fear UC Berkeley roots might be a potential group for Harris to rally. If that happens, and Harris wins here, it could be the end of Biden.”