Kamala Harris Bolsters Biden for 2024 and Lays Groundwork for 2028

For decades, ambitious politicians with eyes on a future presidential run made pilgrimages to Iowa and New Hampshire, casually popping in at fairs and local fund-raising dinners as if they just happened to be in the area.

When President Biden pushed Democrats to place South Carolina first on their presidential primary calendar, the geography for the party’s political strivers changed. They are now working to build support not in mostly white Northern places but in a Southern state with a predominantly Black primary voting base that better represents the modern Democratic Party.

So when Vice President Kamala Harris arrived on Friday in Orangeburg, S.C., for her ninth visit to South Carolina since taking office, she came as a known quantity. While she and Mr. Biden are running for renomination without serious challengers, the relationships she has developed in the state are expected to play a part in lifting their ticket to a comfortable triumph on Saturday in the party’s first recognized primary election.

Ms. Harris’s trip, as well as an ongoing college tour to defend abortion rights and promote the Democratic agenda, also served two larger purposes: working to shore up Mr. Biden’s lingering vulnerabilities with Black voters and young voters, and keeping the first woman and first woman of color to serve as vice president at the forefront for the next presidential contest in 2028.

Perhaps the most influential Democrat in South Carolina is already on board with Ms. Harris as a future White House candidate.

“I made very clear months ago that I support her,” said Representative James E. Clyburn, whose 2020 endorsement of Mr. Biden before his state’s primary election helped rejuvenate the former vice president’s struggling campaign and carry him to the nomination. “That’s why we got to re-elect the ticket. Then you talk about viability after that.”