Donald Trump, self-promoter extraordinaire, may turn out to be his own worst character witness as he faces a stampede of new sexual-assault allegations.

If the Republican presidential candidate makes good on threats to sue the New York Times and other media outlets for reporting that he groped and kissed more women without their consent, he won't just be challenging major media entities unlikely to be cowed by such litigation. He'll also be inviting much deeper scrutiny into his entire sexual history, and more.

Michelle Obama attacks Trump's comments about women 1:36

This widespread probing occurs in the pretrial stage known as discovery. And it's doubtful that even attention-seeking Trump would find this new level of exposure at all titillating.

Discovery allows each side in a lawsuit to learn details about the opposing counsel's case.

"In cases like this, discovery tends to be extraordinarily expansive, and it's just difficult to believe that Mr. Trump wants to open himself up to that kind of inquiry," says Len Niehoff, who teaches media law at the University of Michigan.

Could seek coveted 'Apprentice' tapes

The Times would be free to ask about things that may not even be admissible as evidence. The newspaper might request, for instance, Trump's entire history of litigation and settlements, or seek information about his past sexual activity.

Jessica Leeds arrives at her apartment building in New York on Wednesday. Leeds was one of two women who told the New York Times that Republican presidential candidate Donald Trump touched her inappropriately. (Julie Jacobson/Associated Press)

Tantalizingly, they might ask for the elusive tapes of unaired and reportedly damning footage from The Apprentice, as well as names and contact details for every female cast and crew member from the reality show that previously starred Trump.

You gotta know there are more [accusers] out there, and they'd be afraid to talk to media. But if they're subpoenaed and they have to give a deposition, Trump can't sue them. - Aviva Orenstein , professor of evidence law at Indiana University

"That would be a fair interrogatory question," says Aviva Orenstein, a professor of evidence law at Indiana University, adding that the process could yield "crazy amounts" of information.

Reports about new alleged victims of unwanted sexual advances from Trump have surfaced in recent days in the Palm Beach Post, Seattle's King5 News, the Guardian and People.

Asked whether Trump's threat of court action could flatten every outlet that pops up with new sex-assault allegations, Niehoff said major media organizations are a different beast from the sort Trump may be used to challenging.

More like a game of 'whack-a-lion'

"These entities have very good lawyers. This isn't a game of Whack-a-Mole," he said. "This is a game of whack-a-lion."

Real estate tycoon Donald Trump gets kissed by his wife Melania, left, and model Heidi Klum at a party in 2008. (Lucas Jackson/Reuters)

The New York billionaire, Niehoff added, is not sitting in the best of circumstances, "given that this is largely a controversy spurred by his own statements and then his own denial that he had engaged in this conduct."

On Thursday Trump denied reports from as many as five women that he victimized them in a similar manner that he described in a 2005 hot-mic conversation with Access Hollywood's Billy Bush.

Republican presidential candidate makes startling counter claims about allegations of sexual impropriety made in the New York Times 2:02

On Wednesday the New York Times published a story quoting Jessica Leeds, 74, who alleges Trump grabbed her breasts and tried to force his hand up her skirt "like an octopus" more than three decades ago, when they sat side-by-side on a New York-bound flight.

The paper also quoted Rachel Crooks, who said she was 22 and working in Trump Tower in 2005 when Trump entered the elevator she was in and, after she introduced herself, kissed her directly on the mouth.

Trump holds up signs at the end of a campaign rally in Lakeland, Fla., on Wednesday. (Mike Segar/Reuters)

The Palm Beach Post published a separate story on Wednesday about Mindy McGillivray, who was 23 and working at Trump's Mar-a-Lago golf course in 2003 when she said Trump groped her.

People magazine reporter Natasha Stoynoff wrote she was also "attacked" in 2005 by Trump, who she says kissed her, "forcing his tongue down my throat" during a tour of Mar-a-Lago.

A June Yahoo News report also resurfaced Wednesday night about Cassandra Searles, Miss Washington USA 2013, who called Trump a "misogynist" and alleged in a Facebook post that he "continually grabbed my ass and invited me to his hotel room."

Controversy of Trump's own making

On Thursday Trump struck a defiant tone at a rally in Florida.

"These claims are all fabricated. They're pure fiction and they're outright lies. These events never, ever happened," he said, before criticizing the women's physical appearances and vowing to prepare a lawsuit against the Times.

Cassandra Searles, Miss Washington USA 2013, competes in her evening gown during a Miss USA preliminary show in Las Vegas in 2013. (Patrick Prather/Miss Universe Organization/Associated Press)

Some of the women who came forward in reports said they feared going public due to Trump's position of power. Trump has also developed a litigious reputation.

But under a discovery process, women who may have been silenced by legal threats, for example, would be compelled to testify if subpoenaed by lawyers.

"You gotta know there are more [accusers] out there, and they'd be afraid to talk to media," Orenstein says. "But if they're subpoenaed and they have to give a deposition, Trump can't sue them for that."

Here it is: Trump campaign lawyer sends letter to <a href="https://twitter.com/nytimes">@nytimes</a> demanding "full and immediate retraction and apology" of article==> <a href="https://t.co/yQpk5lgGOB">pic.twitter.com/yQpk5lgGOB</a> —@frankthorp

The NYT attorney seems to want Trump to sue, read to the end. <a href="https://t.co/rhlqnp2nTf">pic.twitter.com/rhlqnp2nTf</a> —@jaketapper

The irony, says Republican strategist Mac Stipanovich, is that so much of this controversy is of Trump's own making, with his admissions caught on tape.

"First, the Access Hollywood tape is released; then at the debate, [moderator] Anderson Cooper asks him three times about whether he's ever assaulted women, and finally he takes the bait" and denies he ever acted out his boasts, Stipanovich said.

Trump delivers a speech on Thursday in Columbus, Ohio. (Evan Vucci/Associated Press)

"It was inevitable as the sun coming up that people would come forward and say he lied."

[ WikiLeaks ] just doesn't compete with grabbing Miss Washington's ass, you know what I mean? - Mac Stipanovich , Republican strategist

Stipanovich, who will for the first time vote for a Democratic candidate in Hillary Clinton this November, allows that Republicans have given Trump multiple lifelines following a series of scandals and controversial statements. Yet there's something about Trump's boasting of predatory sexual behaviour in the leaked tape that pushed many high-ranking Republicans over the edge and led to the cascade of withdrawals of endorsements.

"It wasn't enough to call Mexicans rapists and drug dealers; it wasn't enough for him to say we're going to torture our enemies and murder their families; it wasn't enough to attack American Muslims for their faith," Stipanovich says.

Lara Trump, Donald Trump's daughter-in-law, speaks during a Women for Trump rally on Wednesday in Albany, N.Y. (Mike Groll/Associated Press)

He chalks the development up to the "cumulative effect" of Trump's mounting controversies, the proximity to election day and the nature of the disclosure.

A WikiLeaks scandal about Clinton campaign operative Jennifer Palmieri allegedly sending an email that might be critical of Catholics "just doesn't register," Stipanovich says.

"That just doesn't compete with grabbing Miss Washington's ass, you know what I mean?"

Trump meets with small business leaders before a campaign rally in West Palm Beach, Fla., on Thursday. (Mike Segar/Reuters)

A so-called "secret majority" may be the last hope of the desperate, he says.

"The people who say, 'Oh, you can't poll Trump supporters. But you wait on election day. They're going to come out of the woodwork! They're marching down from the mountains! And all these old white men without college educations are going to sweep Trump into office.'"

Very doubtful, Stipanovich says. The latest RealClearPolitics polling average has Clinton at 48.1 percentage points to 41.4 per cent for Trump, putting her 6.7 points ahead.

At this point, Stipanovich believes, "all Hillary has to do now is keep her foot on his throat."