Pop star Taylor Swift endorsed Vice President Kamala Harris for president on Tuesday night, minutes after the Democratic candidate ended a heated debate with Donald Trump.

“I’m voting for @kamalaharris because she fights for rights and causes that I believe need a warrior to support them,” Swift said in a statement on her Instagram account, which has more than 280 million followers.

“I think she is a steady, talented leader and I believe we can accomplish so much more in this country if we are led by calm and not chaos,” Swift wrote under a photo of herself holding a cat.

“I was so encouraged and impressed by her choice of running mate @timwalz, who has been advocating for LGBTQ+ rights, IVF, and women’s right to own their own bodies for decades,” Harris said, referring to Minnesota Gov. Tim Walz.

Swift signed the post with her full name and as “Childless Cat Lady,” an apparent attack on Trump’s Republican nominee, Sen. J.D. Vance of Ohio.

Since his nomination in July, Vance has been criticized for comments he made in 2021 in which he called several top Democrats, including Harris, pitiful “childless cat ladies” who “want to make the rest of the country feel pitiful,” and called them hostile to the family and hostile to children.

Swift wrote that she recently “learned that an AI of ‘me’ had been posted on his site that falsely supported Donald Trump’s presidential campaign.”

“It really brought up my fears around AI and the dangers of spreading misinformation,” she wrote. “It made me realize that I need to be very transparent about my real plans for this election as a voter. The easiest way to combat misinformation is with the truth.”

Two Harris campaign officials told NBC News that the timing of Swift’s endorsement was a surprise to the campaign.

But the singer supported President Joe Biden and his then-running mate Harris in the 2020 election.

When asked by reporters on Tuesday about Swift’s support for Harris, Trump said, “I have no idea.”

“I did my research and made my choice,” Swift wrote.

“Your research is entirely yours to do, and the choice is yours to make. I also want to say, especially to first-time voters: remember that in order to vote, you must be registered!” she wrote.

“I also find it much easier to vote early. I will post a link in my story where you can register and where you can find the dates and information for early voting.”