Nikki Haley criticized Donald J. Trump on Friday, saying, “America can do better than Donald Trump and Joe Biden,” after a Manhattan jury had ordered the former president to pay $83.3 million for defaming the writer E. Jean Carroll.

It was the latest iteration of Ms. Haley’s new attack line against Mr. Trump, portraying another Trump presidency as just as bad for the country as another four years of President Biden. Ms. Haley, the former governor of South Carolina, began making similar statements after Gov. Ron DeSantis of Florida dropped out of the race on Sunday, leaving her as the last serious threat to Mr. Trump’s candidacy.

“Donald Trump wants to be the presumptive Republican nominee and we’re talking about $83 million in damages,” Ms. Haley wrote on social media, adding that Mr. Trump’s legal troubles continued to be a distraction. “We’re not talking about fixing the border. We’re not talking about tackling inflation.”

Ms. Haley is preparing for what may be the final stand of her presidential campaign, facing off against Mr. Trump next month in a critical primary in her home state of South Carolina. Ms. Haley has largely avoided commenting on Mr. Trump’s legal cases, but the former president leads her by wide margins in polls, and she appears to be turning up the heat in an effort to catch him.

Mr. Trump lashed out on social media soon after the verdict, attacking the civil trial as a “Biden Directed Witch Hunt” despite the fact that Ms. Carroll sued Mr. Trump in 2019, before he had left office and while Mr. Biden was just one of many Democratic presidential candidates.

The verdict was an extraordinary moment for a front-runner in a presidential nominating contest. A jury penalized Mr. Trump $83.3 million for defamation just three days after he had won a second nominating contest — in New Hampshire, by 11 percentage points. Mr. Trump also faces 91 felony counts in four separate criminal cases.