Get breaking news alerts and special reports. The news and stories that matter, delivered weekday mornings.

Dealing a major blow to Bill Cosby, a Pennsylvania judge ruled Thursday that five more accusers can testify against the entertainer when he is retried on charges he drugged and molested Andrea Constand.

Cosby's spokesman, Andrew Wyatt, downplayed the impact of the decision.

"It shows how desperate they [prosecutors] are, and this is a very weak case," he said in a text message. "Mr. Cosby is innocent of these charges."

But one legal observer who has been following the case said it's devastating for the defense, with the trial set to play out against the backdrop of a national reckoning over sexual misconduct by powerful men.

"It's the iceberg to the Titanic," said William Brennan, a prominent Philadelphia criminal defense attorney.

Brennan said Cosby is dealing with a brand-new legal team, the #metoo movement and, now, the specter of emotional testimony from five women who say they were sedated and sexually assaulted between 1982 and 1996.

The Morning Rundown Get a head start on the morning's top stories. This site is protected by recaptcha

"It seems like the trifecta of bad luck for Mr. Cosby," he said.

Cosby, 80, has been accused of a range of sexual misdeeds by dozens of women since the scandal erupted in 2015. The comedian denies all the allegations and says his 2004 encounter with Constand at his Pennsylvania home was consensual.

At his first trial, prosecutors wanted to bring 13 women to the stand in addition to Constand to show the jury a pattern of behavior, but Montgomery County Judge Steven O'Neill allowed them just one extra accuser — Kelley Johnson, who worked for his talent agent and claimed she was drugged and assaulted in a hotel room.

The jury deadlocked and the judge declared a mistrial, setting the stage for the retrial that begins next month.

Bill Cosby arrives with publicist Andrew Wyatt for a pretrial hearing on March 6, 2018. Bdrendan McDermid / AFP - Getty Images

This time around, prosecutors sought permission to have 19 accusers testify, relying in part on a legal theory called the doctrine of chances that was recently accepted by a Pennsylvania appeals judge and says the more something happens the less likely it's a mistake.

Prosecutors argued that the string of accusers shows Cosby could not have believed Constand gave her consent.

"The facts underlying each prior victim's testimony are remarkably similar to the facts underlying Ms. Constand's claims," they wrote in a brief.

"They establish the defendant followed the same script with each victim: he established himself into a position of trust and respect, sedated each victim with an intoxicant, and sexually assaulted each victim while they were incapacitated and unable to resist."

The defense countered that the various accounts were not similar beyond the fact that most had not reported the alleged abuse to anyone at the time. Cosby's lawyers said that in the current climate, it would be too inflammatory to have even one woman from the past take the stand.

"Permitting testimony from 19 accusers to establish prior bad acts, or even any number close to it, would be unprecedented," the defense wrote in a brief. "Likewise, permitting evidence of decades-old acts would also be a first."

In a written ruling, the judge said prosecutors can select five witnesses from a group of eight. The eight, who are referred to by numbers court papers, say they were abused between 1982 and 1996.

"We are reviewing the Judge’s order and will be making some determinations," prosecutors said in a statement.

Dennis McAndrews, a former Pennsylvania prosecutor who attended the first trial, called the order "a potential game changer."

"It is far easier for a juror to dismiss the impact of one additional victim than five additional alleged victims," McAndrews said, adding that the new witnesses could make up for any inconsistencies or gaps in Constand's testimony.

He said the the defense could appeal the ruling, but noted "the appellate courts rarely entertain such pretrial appeals."