Following an impromptu invite by the star, presidential hopeful Clinton visited the Scandal set in Los Angeles, giving her team the perfect opportunity to promote her campaign.

"I'm really close to the campaign. I had recorded a few radio spots... Hillary was in town for a fundraiser, and Tony (Goldwyn, who plays President Fitzgerald Grant) and I thought we might get off work in time to go, but we didn't," the actress told Adweek in her April cover interview.

"So I emailed Huma (Abedin, Clinton's longtime aide) and said, 'Why don't you guys come here?' And they were able to," she recalls, joking that it was difficult to tell at one point who was, "Secret Service on the show, and the real Secret Service."

Kerry has been a vocal supporter of Hillary's campaign. Last month (Mar16) she debuted an ad alongside Scandal producer Shonda Rhimes and How To Get Away With Murder star Viola Davis, in which the stars echoed the politician's campaign catchphrase "I'm with Hillary."

Kerry revealed the campaign spot was the idea of the politician's aide Huma, and she thinks she may have been inspired by Hillary's visit to the Scandal studio.

"I can't imagine it hadn't been slightly inspired by her visit," she admitted. "This was not dictated from above, from Shonda. And it came together remarkably fast. We did it on a Saturday, and I think a couple of days later it was on national television."

With the support of celebrity backers like Kerry, Hillary is currently leading the Democratic presidental candidate race.