In the campaign ad, which was directed by Washington's Scandal co-star Tony Goldwyn and a tightly held secret ("We were shocked it didn't leak before it got to air," a Clinton campaign adviser tells PEOPLE), the TV-industry power women take turns with the script:
"Every day, I wake up and play a brilliant, complex, overqualified, get-it-done woman who obsessively fights for justice, who care, who gives a voice to the voiceless, who gets knocked down and always gets back up."
Rhimes interjects that she writes television characters who are, the actors continue, "strong but flawed, human but extraordinary."
And if ShondaLand's TV world has Olivia, Meredith and Annalise, the actors continue, "the real world has Hillary Clinton – a bonafide rolls-up-her-sleeves, fights-for-what's-right, in-it-for-you, won't-back-down, champion for us all," the women say in the ad.
Goldwyn tells PEOPLE that, on the Scandal set, he and Washington and the cast talk about the 2016 presidential campaign "daily." And in the ShondaLand family, there is such a sense of "real urgency" about the election that the ad came together on a recent Saturday morning with top talent – including Oscar-winning cinematographer Janusz Kaminski and Goldwyn's wife, the movie production designer Jane Musky – donating their time without hesitation.
"It was absolutely a passion project for a bunch of super-busy people and a testament to how much we feel a responsibility to use our platform and our voice," Goldwyn said in an interview.
Asked to envision a general-election face off between Clinton and Republican front-runner Donald Trump, Goldwyn says such a race will be "depressingly vicious, brutal, very, very rough."
"Donald Trump is kind of a genius at the sucker punch, but Hillary's a fighter and I don't think she's scared."
While the ad was kept under wraps before Thursday night, the stars' support for Clinton has been widely broadcast – at Clinton campaign fund raisers, on the campaign trail and on the celebs' social media.
Goldwyn campaigned for Clinton in Iowa, ahead of that state's January caucuses (which she won), and then accompanied the candidate to Tennessee ahead of its "Super Tuesday" primary (which she won). He was headed next to Arizona to campaign ahead of the March 15 voting and said he wouldn't mind making more campaign ads – next time starring Clinton herself.
"The part of her story that gets left out is that she's been indefatigable in fighting for families and women and children since she was in college," says Goldwyn. "I have two daughters in their twenties and Hillary's the one who is going to create a playing field where my girls can have genuine equality."
Barbara Kinney for the Clinton Campaign
Says Goldwyn, "We all feel a sense of personal urgency. So when the idea of the ad came up, everyone just said, 'Yeah! Let's do it.'"