The lawsuit of E. Jean Carroll, the columnist who says President Trump raped her in the 1990s, is playing out in a Manhattan courtroom, featuring vivid testimony from Ms. Carroll herself. So could this case strike a major blow at Mr. Trump, already facing criminal charges in a different case and possibly more criminal charges down the road? Or is Ms. Carroll’s suit an unserious sideshow from which the former president will eventually emerge victorious, and unbowed?

Certainly the alleged facts of the case are sordid enough to give Stormy Daniels a run for her money.

In a 2019 memoir, Ms. Carroll claimed that Mr. Trump sexually assaulted her in a dressing room at the luxury Bergdorf Goodman department store in the mid-1990s (she can’t remember the exact year). The future president had cornered her, she said, by asking her to try on some lingerie. Two of Ms. Carroll’s friends say they recall her telling them about the event at the time it allegedly occurred. 

After Mr. Trump flatly denied her account, saying she was “not my type,” Ms. Carroll filed a lawsuit in the New York County supreme court on charges of battery and defamation. 

“Decades ago, the now President of the United States raped me,” she said as she announced the lawsuit in November 2019. “When I had the courage to speak out about the attack, he defamed my character, accused me of lying for personal gain, even insulted my appearance.”

(Mr. Trump has continued to denounce and insult Ms. Carroll. He referred to her this week as “Miss Bergdorf Goodman” in a posting on Truth Social. The former president dismisses her narrative as absurd. He was too famous at the time, he says, to have been able to spirit anyone away into a dressing room. He also argues that there’s no way a floor at Bergdorf Goodman — by many estimations the premier department store in New York City — would be empty enough, and sufficiently staff free, to allow for the predations Ms. Caroll describes.)

Since the legal proceedings began on Tuesday, lawyers for both parties have made their opening statements and Ms. Carroll has spent hours on the witness stand. 

On Wednesday, she told the jury what she claimed happened in either 1995 or 1996. She said she was suing because the former president “lied and shattered” her reputation by saying she fabricated the event and mocked her appearance. After recounting her story to the jury, Ms. Carroll began to cry, saying, “You ask me what I did in that moment. I always think back to why I walked in there.”

While on the stand, Ms. Carroll acknowledged that she attended a party alongside so-called anti-Trump resistance stars before she filed her lawsuit, raising speculation that some high-profile detractors of Mr. Trump pushed her into suing. During a 2019 party at the Manhattan home of a liberal writer, Molly Jong-Fast, Ms. Carroll met the left-wing comedian Kathy Griffin and a conservative lawyer, George Conway, the estranged husband of Mr. Trump’s chief strategist. 

When asked in court on Thursday if her dinner with those fiercely anti-Trump celebrities affected her decision to sue, Ms. Carroll said that Mr. Conway’s advice “crystallized” her final move to file the lawsuit. 

Ms. Carroll’s civil lawsuit seeks financial damages, so even if Mr. Trump loses badly in court, he will not face criminal liability or go to prison for rape, as did disgraced film producer Harvey Weinstein. What Mr. Trump does risk, though, is being the first former or current president to be held accountable in court for a sex crime.

Regardless of the trial’s outcome, Mr. Trump, who is not required to appear in court, must confront the unseemly spectacle of having the alleged sexual depravities of his notorious playboy years scrutinized in great detail before a jury.

How will all this bad publicity play out, with the former president already facing criminal charges related to his alleged dalliance with a porn star?

It is not the first time the former president has faced legal action over his personal life. Given that he is the first American president to be indicted, we now have evidence that legal scrutiny actually makes Mr. Trump even more popular among his fellow Republicans. After he was indicted by a grand jury at Manhattan, one poll showed the former president received a slight bump in support. Today, 37 percent of Republicans say they are more supportive of Mr. Trump than the party itself — up from 33 percent in March. 

On March 17 — the day before the former president announced on Truth Social that he would be arrested — he led Governor DeSantis in a hypothetical national Republican primary poll by a margin of 51 percent to 29 percent. Today, Mr. Trump leads Mr. DeSantis by 59 percent to 21 percent. 

However, an Ipsos poll found that independent voters have only been more turned off by Mr. Trump in the wake of the indictment. In total, 57 percent of American independents believe the former president committed a crime. 

Yet the tonnage of the sordid details in the Stormy Daniels case combined with the allegations from Ms. Carroll could have a cumulative effect on voters making judgment calls about the former president’s character. 

There was no police report at the time of the alleged assault of Ms. Carroll — something Mr. Trump’s defenders often point out. As noted earlier, Ms. Carroll can’t even pin down the exact year of the alleged rape. Previously, civil suits for battery and defamation carried a statute of limitations of just three years, so Ms. Carroll technically should not have been able to sue after 1999. Yet in 2022, New York state adopted the Adult Survivors Act, which gave people a window in which to sue their alleged assailants even if the statute of limitations had expired. 

If Mr. Trump is found criminally liable, he could see himself forced to write a check to a woman he says is a liar who is “not his type.” If he wins this round, Ms. Carroll could appeal to higher state courts, potentially dragging the legal proceedings well into the height of the presidential race.

All the embarrassment and inconvenience from Ms. Carroll’s suit would come on top of an expected criminal indictment from Fulton County, Georgia, over election fraud allegations and whatever may come from the biggest threat of all to Mr. Trump: the special prosecutor investigating his alleged mishandling of classified documents and involvement in the events of January 6, 2021.  

Ms. Carrol’s lawyer, Shawn Crowley, told the jury that this lawsuit was filed in order “to clear her name, to pursue justice, and to get her life back.” Mr. Trump’s lawyer, Joe Tacopina, countered in the courtroom, saying Ms. Carroll “became a celebrity and loved every minute of it.”

The trial is expected to last one to two weeks.