David Gergen is a senior political analyst for CNN and has been a White House adviser to four presidents. He is a professor of public service and co-director of the Center for Public Leadership at the Harvard Kennedy School. Follow him on Twitter: @david_gergen . Martha Pease advises Fortune 100 companies and business leaders on corporate strategy, marketing and transformational growth. She is the author of the book " Think Round ." The opinions expressed in this commentary are solely theirs.

(CNN) It was certainly a magic moment -- hundreds of thousands of women pouring hour after hour into the Mall in Washington, joined in protest by women in dozens of American cities and even in a half dozen or more big cities overseas. All told, reported the Washington Post , millions marched to champion their rights and those of others, one of the biggest crowds in recent years.

But it could well be more than a moment in time. Donald J. Trump may have done something that Bernie Sanders, Hillary Clinton, and even Barack Obama could not do: spark the creation of a progressive movement that massively resists an America that goes backward.

Without any doubt, this Women's March -- with all of its excitement, its inspiration, its glory -- has given millions of women and men fresh hope that their dreams of an inclusive, compassionate America can be protected and flourish. Now the really hard work begins.

"It was freaking amazing," texted one marcher, capturing the sentiments of so many.

"People are disgusted, angry. This was more than a moment. It was an awesome communal experience. Everyone was so kind to one another. I think many more people, especially young people, will go into politics."

There are still many skeptics, of course. Another marcher wrote to us that it was unlikely to lead to real change. "We need to keep the torch lit," she added. Among Republicans, there was a tendency to play down the significance of the march. Senator Rick Santorum pointed out on CNN, for example, that women had marched many times before and Congress paid virtually no attention.

On the day of the March, President Trump -- extraordinarily -- decided not to say anything at all. His new White House team issued no public statement on his behalf and Trump sent out only a single tweet during the day, focusing on his visit that afternoon to the CIA. One might have thought they would invite in some of the protestors to the Roosevelt Room and have a quiet conversation about their fears with the President and daughter Ivanka, tapped to advise him on the education and empowerment of women and girls. As with the Inaugural Address, they missed another big opportunity for bridge building.

But talking to the women who flocked to DC, it was clear they have written off Trump and his male-dominated team. Many of them were distraught by Hillary's loss and have been in near-mourning since. They have a deep, chilling fear that Roe v Wade (the anniversary of which is today) will actually be overturned and they will lose control not only of their bodies but of their basic rights and destinies. This fear transcends gender; their anxiety is that over time the rights of all vulnerable citizens will be eroded.

They decided weeks ago to stand up and fight, and they were overjoyed to find so many other women -- and lots and lots of men -- spontaneously joining them. The most touching scenes were of women in their 50s and 60s coming with their daughters, women pushing strollers, some women in wheel chairs, and men in those same pink hats. The march seemed an enormous catharsis, an astonishing and inspiring discovery that they have masses of allies.

There is already a folklore on how this all came about: the day after the elections, a grandmother and retired attorney in Hawaii, Teresa Shook, created a Facebook page suggesting a march at the Trump Inauguration. According to Vogue , "She went to bed. By the time she woke up, 10,000 had affirmed the plan." A second woman, Bob Bland, posted a similar call on Facebook and had quick results. Both white, they reached out and got African Americans, Muslims, Latinas and others to help organize. As with Tahrir Square, technology unleashed the power of pent-up passions.

The question now is whether the protestors can turn the magic moment into a movement and if so, what it would look like. There are certainly plenty of leaders, young and old alike, who want to pitch in -- just watch the speeches from various locations on Saturday of Gloria Steinem, America Ferrera, Elizabeth Warren, Cory Booker and others. They know it will be hard, that money must be raised, that internal tensions must be resolved, that passions must be sustained, and that Trump and his allies on Capitol Hill hold the high ground. Fundamental change can take a generation or more, as the suffragists discovered more than a century and a half ago

The times today are different, though. Women feel more than ever their right to stand up to men who want to take them backwards. As one marcher said to one of us, "Trump represents every man who tries to keep us down. We'll be reminded of that every single day for the next 4 years." Then she added, "That's an incredibly motivating target."

One marcher's sign said "Make America Compassionate Again", a goal that carries even more import in the face of Trump's dark vision of a country wallowing in self-centered isolationism. There's also the intense personal commitment that hundreds of thousands of women made to protect and support each other in the march -- and that many want to keep over the coming years. These are motivators that may prove to be game changers going forward.