When Christine Blasey Ford appears at a hearing of the Senate Judiciary Committee today, she is sure to be asked why she waited 35 years to make public her accusation that the Supreme Court nominee Brett Kavanaugh had sexually assaulted her when they were both in high school in the early 1980s.

Donald Trump has asked similar questions, implying that the delay cast doubt on the credibility of her accusations. Last week, he tweeted: “I have no doubt that, if the attack on Dr Ford was as bad as she says, charges would have been immediately filed with local Law Enforcement Authorities by either her or her loving parents. I ask that she bring those filings forward so that we can learn date, time, and place!”

He doubled down on Tuesday, telling reporters at the United Nations that another woman who has accused Kavanaugh of sexual misdeeds, Deborah Ramirez, was unreliable because she had been “totally inebriated and messed up” at the time of the incident.

“Thirty-six years ago? Nobody ever knew about it? Nobody ever heard about it? And now a new charge comes up,” Trump said. “I can tell you that false accusation and false accusations of all types are made against a lot of people.”

Such comments have prompted an outcry of tweets using the hashtag #WhyIDidntReport about the many reasons why victims don’t report sexual abuse. But Trump’s tweet and remarks also don’t account for a critical reason why the alleged victims reported the incidents only now: The behaviour of the President himself.

Change in America happens slowly. The political scientist John Kingdon argued that, to get people to think differently, activists must spend years “softening” them up. So the #MeToo movement has its roots in generations of feminist activists who slowly changed perceptions and policies to help prevent violence against women.

But, usually, something else also needs to happen for Americans to change. Kingdon says that an idea’s time has to have come. Take the Egyptian revolution, for instance. Clearly the triggering event was the revolution in Tunisia, as Egyptians watched the people of another Arab state topple a dictator.

To find the triggering event for the #MeToo movement, you need to look no further than Trump.

In an Access Hollywood tape that surfaced one month before the 2016 presidential election, Trump can be heard bragging that when he found women attractive, he would “grab them by the p***y” — and get away with it. “When you’re a star, they let you do it,” he said. “You can do anything.”

While he largely brushed off the Access Hollywood incident and went on to win the White House, Trump has been accused of sexual misconduct by more than a dozen women. In addition, he has repeatedly demeaned women — including France’s First Lady, Brigitte Macron — by commenting openly on their bodies. In September 2017, just before the #MeToo movement started, Trump retweeted a video that was edited to make it look like he was swinging a golf club and knocking Hillary Clinton down. At the time, I argued that the President’s post had made the world a little less safe for women, as studies show that exposure to violence in the media makes people more likely to commit acts of violence.

Such raw eruptions of misogyny from the highest authority in the land had women fed up. In October 2017, they started reporting incidents of sexual abuse en masse. This was probably due in significant part to a desire to resist the very culture of sexism and sexual abuse that Trump was promoting.

The first women to accuse the producer Harvey Weinstein were actresses such as Ashley Judd and Asia Argento. They started to break down the stigmas associated with reporting sexual abuse and demonstrate for other women that even the most powerful men can be held accountable for sexual crimes. Also, their celebrity status lent them credibility in their claims and made it likely that they would be emulated by other women. Soon, women in many other industries were coming forward with their own stories of sexual abuse — including President Reagan’s daughter, Patti Davis.

The #WhyIDidn’tReport is an outgrowth of #MeToo, a response to the criticism of Ford for waiting so long to come forward with her accusations against Kavanaugh. Of course, as users of the #WhyIDidntReport hashtag make clear, many women, not only Ford, decide not to report an incident at the time it happened. Ford was young and scared. There would probably be social repercussions to accusing someone in her social circle. She didn’t have proof. Perhaps she feared being blamed for instigating the event herself, which remains a common occurrence for victims.

But the main reason she waited is that, until now, Kavanaugh wasn’t in the running for one of the most powerful decision-making posts in the nation, which can only have led her to believe she had a responsibility to provide information that, if true, would have a direct bearing on the judge’s character.

But there’s another critical factor. The #MeToo movement is happening and there’s no way to stop it now. Women have seen by example that they can hold powerful men to account.

As Victor Hugo wrote, “greater than the tread of mighty armies is an idea whose time has come”. And the person Trump has most to thank for triggering this movement — and thereby potentially thwarting his nominee — is himself.

• Kara Alaimo is an assistant professor of public relations at Hofstra University and author of Pitch, Tweet, or Engage on the Street: How to Practice Global Public Relations and Strategic Communication. She previously served in the Obama Administration