Nathaniel, I think that another explanation for Haley’s continued presence in the race is less political and more personal. Clearly, the two candidates don’t get along, and never really have. (Remember that the only reason Trump even tapped Haley as ambassador was as a favor to then-Lt. Gov. McMaster.) With the race getting increasingly chippy and personal, I think Haley may be staying in for longer than politically savvy because she knows just how much it gets under Trump’s skin. This is, after all, a politician who sells shirts that say "Go ahead and underestimate me, that’ll be fun."

—Jacob Rubashkin, Inside Elections

It was pretty clear Trump was going to be the nominee after New Hampshire. I think maybe Haley could be forgiven for trying to stay in for a couple more weeks to see if she could move the needle in South Carolina, a state she knows so well. But after it was clear that Trump’s polling lead wasn’t shrinking, she lost any practical justification for staying in the race.

—Nathaniel Rakich, 538

Shortly after quickly being projected the winner, Trump took to the stage and thanked his supporters. He said his victory tonight would be repeated in November, when they'd gather to tell Biden he was fired. Nine months is a long time to wait, he said, and he asked Gov. Henry McMaster, who was on the stage with him, if there was anything he could do to speed it up. "In certain countries, you're allowed to call your election date," he said, and added he would speed it up if he could. Rather than give a long speech himself, though, he shared the stage with McMaster and the states two Senators, Graham and Scott, who both condemned Trump after the Jan. 6 insurrection. Scott was until recently trying to oust Trump as the presumptive nominee, but Trump said he'd done a better job advocating for him than he had for himself. "I'm just very happy he didn’t have that same energy, drive because I probably would have been out of the race a long time ago," Trump said. Scott took to the stage and asked in a country growl, "Is South Carolina Trump country???" fully in campaign mode. The crowd booed Graham, who spoke flatteringly of Trump regardless.

—Monica Potts, 538

Was there any point besides principle in Haley staying in up until tonight? The writing has been on the wall for weeks, and getting trounced in her home state is a humiliation she could have spared herself. This obviously just makes the inevitable even more apparent, but if she didn’t drop out after New Hampshire, what’s a couple more weeks on principle? (Assuming she has enough money to continue campaigning through Super Tuesday, that is.)

—Kaleigh Rogers, 538

Haley addressed supporters at about 8:30 p.m. Eastern, and vowed to stay in the race: "I said earlier this week that no matter what happens in South Carolina I would continue to run for president, and I’m a woman of my word," she said. Haley said she was frustrated and worried about the future of the country and the world, and that she was running to save it. "America will come apart if we make the wrong choices," she said. Again, Haley presented her case as one of electability. She said that we couldn't live with four more years of Biden's failures or Trump's lack of focus, and that the voters in future primaries deserved a choice, not a "Soviet-style election" with one candidate. With about 40 percent of the vote (as of now), she noted that it was roughly the same amount she'd gotten in New Hampshire. "I’m an accountant. I know 40 percent is not 50 percent," she said. "But I also know 40 percent is not some tiny group." Those people were looking for an alternative, and she said she shared their frustration. The electability argument is one that Republican primary voters aren't buying.

—Monica Potts, 538