Watch Katy Perry perform on the campaign trail for her pal, 'Hilly C'

Should there be a Hillary Clinton presidential library one day, an entire wing devoted to Katy Perry's show-stopping looks from the campaign trail may be in order.

The pop star, who has made it abundantly clear that she's #WithHer, headlined a concert supporting the Democratic presidential candidate in battleground state Pennsylvania on Saturday night.

"I admire so many things about Hilly C," Perry told the crowd who, in turn, roared.

SEE ALSO: Watch Katy Perry valiantly attempt to vote nude in new video

Perry took the stage at West Fairmount Park in Philadelphia to Janet Jackson's "Nasty" for no particular reason. Just a fun song!

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Perry's look for the evening was created by Prabal Gurung, one of Michelle Obama's favorite designers. Her extravagant blue coat read, "I'm with Madame President," which she took off to reveal a sequined flag minidress.

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Perry's speech touched on her own experience growing up in a "staunch Republican" family and urged voters to support the candidate they believe is best for the future even if they disagree with their loved ones' politics.

Perry performed her hits, "Dark Horse" and "Firework." Naturally, her microphone was blue.

You can watch the full event, which also features an appearance by Shonda Rhimes, below. "That woman has zero chill," Rhimes said, endorsing Clinton. "Her brain is always working, always thinking, always on."