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 spent a good portion of her speech attacking Trump and Biden in equal measure. It definitely raised the specter of a third-party candidacy down the line, after she loses the GOP nomination, perhaps on the No Labels ticket. Haley has said she’s “not interested in talking” with the centrist group, but that doesn’t mean she can’t develop an interest later on.

And it’s not entirely unheard of for a losing GOP candidate to launch a more center-minded independent bid for president against an incumbent Democrat and the Republican who beat them in the primary. Illinois Rep. John Anderson did just that in 1980 against Jimmy Carter and Ronald Reagan. He ultimately won about 6.6 percent of the vote (5,719,850 popular votes, but no electoral votes).

—Jacob Rubashkin, Inside Elections