In January 2018, when she first saw reports that her husband had paid off a porn star, Melania Trump was furious. She jetted off to Palm Beach, leaving the president to languish in Washington. She eventually returned, only to take a separate car to Donald J. Trump’s first State of the Union address.
As a criminal trial against Mr. Trump opened on Monday, on charges that he had falsified records to cover up that sex scandal involving Stormy Daniels, Mrs. Trump did not appear. She has long privately referred to the case involving Ms. Daniels as “his problem” and not hers.
But Mrs. Trump, the former first lady, shares his view that the trial itself is unfair, according to several people familiar with her thinking.
In private, she has called the proceedings “a disgrace” tantamount to election interference, according to a person with direct knowledge of her comments who could not speak publicly out of fear of jeopardizing a personal relationship with the Trumps.
She may support her husband, but Mrs. Trump, whose daily news habit involves scouring headlines for coverage of herself, is bound to see headlines involving Mr. Trump and Ms. Daniels that could reopen old wounds. On Monday, Justice Juan M. Merchan, the judge presiding over the case, also said that Mrs. Trump could be among the potential witnesses as the trial gets underway.
All of this could put Mr. Trump on shaky ground with his wife, who has defended him in some critical moments — including when he bragged on tape about grabbing women by their genitals — and withheld her public support in others, like when she did not appear alongside him as he locked up victories on Super Tuesday.
“At the end of the day, she can make or break his candidacy,” said Stephanie Grisham, Mrs. Trump’s former press secretary who resigned on Jan. 6, 2021, and went on to write a memoir. “And at the end of the day, she could probably make or break him.”
Some of the more personally damaging details of Mr. Trump’s behavior may not come up in court. On Monday, Justice Merchan barred some testimony related to the timing of a reported affair between Mr. Trump and a former Playboy model, Karen McDougal. The National Enquirer, which has longstanding ties to Mr. Trump, bought the rights to Ms. McDougal’s story for $150,000 and then never published it — a practice known as “catch and kill.”
Jurors may hear about the relationship between Mr. Trump and Ms. McDougal, Justice Merchan ruled — but not accounts that the affair continued while Mrs. Trump was pregnant with their son, Barron. (If the court proceedings bring up Barron, whose privacy his mother fiercely guards, Ms. Grisham said, Mrs. Trump is likely to be “not happy” with her husband “all over again.”)
The trial is nonetheless all but certain to examine a timeline that Mrs. Trump would prefer not to revisit. Mr. Trump and Ms. Daniels met at a 2006 celebrity golf tournament, at a time when the Trumps had been married for a year and Mrs. Trump had recently given birth to Barron.
Mr. Trump has denied having a sexual encounter with Ms. Daniels. But prosecutors say that when Ms. Daniels looked to sell her story a decade later, Mr. Trump directed Michael D. Cohen, then his lawyer and fixer, to pay Ms. Daniels $130,000 to keep quiet. The reports of a payoff blindsided Mrs. Trump, who responded to the initial reports by getting out of town.
She canceled a trip to Davos, Switzerland, with Mr. Trump, made an impromptu visit to the Holocaust Memorial Museum, and then she jetted off to Mar-a-Lago, the Trumps’ beachside fortress in Palm Beach, Fla., where she spent part of her trip relaxing at the spa. She eventually reappeared, only to take a separate car to Mr. Trump’s State of the Union address and appear on the arm of a male military aide.
By now, allies of the Trumps say, Mrs. Trump has lumped the trial into all of the other legal problems her husband faces, and she is steelier than she was before.
Last month, she appeared next to Mr. Trump to welcome Viktor Orban, the prime minister of Hungary, during a visit to Mar-a-Lago. Weeks later, she voted alongside Mr. Trump in Florida, where she responded to a question about whether she would be campaigning more often with a cryptic “stay tuned.”
Supporters have hailed her scheduled appearance at a fund-raising event for the Log Cabin Republicans, a group of L.G.B.T. conservatives, as proof that Mrs. Trump is prepared to be more engaged on the campaign trail.
The event, scheduled for Saturday, will draw attendees who have paid at least $10,000 for a chance to interact with Mrs. Trump, according to a person familiar with the planning who was not authorized to detail it.
The event will be set up like a cocktail reception, and Mrs. Trump is expected to deliver remarks about her time as first lady and reiterate her support for her husband.
But there is one catch: The event will not be held in a battleground state or at any location on a traditional campaign trail. It will be held in a reception room at Mar-a-Lago, steps from Mrs. Trump’s suite.
The Log Cabin Republicans have been a source of income for Mrs. Trump before. According to a financial disclosure last year, Mrs. Trump received a $250,000 payment from the group in December 2022. Charles Moran, a representative of the group, said in an email that Mrs. Trump was not taking a fee from the Log Cabin Republicans for her appearance.
A spokeswoman for Mrs. Trump did not respond to a request for comment for this article, and neither did a representative for the Trump campaign.
Mrs. Trump’s allies say that she will likely appear again as the campaign continues — a sign, they say, that she realizes there is a real chance she could become first lady again — but that she is likely to be selective with her time.
For now, she is focused on Barron’s graduation from high school later this spring and preparing him for college. Mr. Trump complained repeatedly on social media on Monday that he might miss his son’s graduation because of the trial. Barron attends a private school near Mar-a-Lago and is expected to graduate in May.
Mrs. Trump’s allies say other personal issues could keep her from the campaign trail. She is said to still be mourning the death of her mother, Amalija Knavs, who died in January and was one of a small number of people in Mrs. Trump’s world who had her absolute trust. Her sister, Ines Knauss, is another confidant, but Ms. Knauss lives in New York City.
Another person Mrs. Trump trusts is Kellyanne Conway, who served as counselor to Mr. Trump in the White House; Mrs. Trump is pushing for Ms. Conway to return to Mr. Trump’s orbit in a formal capacity, a development first reported by the news site Puck. Ms. Conway, who was a confidant for both Mr. and Mrs. Trump when they were in the White House, has said that Mr. Trump cares deeply about his wife’s opinion — and, in some cases, he might even fear it.
“He listens to many of us,” she told a congressional committee in 2022, “but he reserves fear for one person, Melania Trump.”
