Trump is the overwhelming front-runner in South Carolina. Here’s the latest.

The polls are now closed in the South Carolina Republican primary and results should start flowing in momentarily.

Former President Donald J. Trump is widely expected to notch another decisive victory over his last major primary rival, Nikki Haley, as he continues his march toward securing the Republican Party nomination for president.

As voters flowed into polling stations in Ms. Haley’s home state earlier in the day, Mr. Trump was more than 500 miles away, near Washington, delivering what was at times a rambling speech at the Conservative Political Action Conference, known as CPAC. In a straw poll of conference-goers, Gov. Kristi Noem of South Dakota and Vivek Ramaswamy tied as the top choice to be Mr. Trump’s running mate.

Mr. Trump, looking past Ms. Haley to the general election, barely mentioned South Carolina during his speech, but he headed to the state afterward. He is set to attend an election-night watch party in Columbia, the capital.

Ms. Haley’s election-night watch party will be in Charleston, concluding her “Beast of the Southeast” bus tour across the state. She had been on a furious drive of campaigning in South Carolina this week and voted earlier in the day in Kiawah Island.

Here’s what else to know: