Former President Donald Trump took aim at Taylor Swift in a Truth Social post Sunday, declaring his distaste for the superstar after she endorsed his opponent, former Vice President Kamala Harris.

“I HATE TAYLOR SWIFT!” Trump wrote in the post.

His announcement emerged online less than a week after Swift revealed publicly for the first time her plans to vote for Harris, the Democratic nominee in this year’s presidential election. Her endorsement followed the first debate on Sept. 10 between Trump and Harris, which saw the two candidates face off during a televised showdown in Philadelphia that covered issues like abortion, immigration, the economy and foreign policy.

“I will be casting my vote for Kamala Harris and Tim Walz in the 2024 Presidential Election,” Swift said in an Instagram post. “I’m voting for @kamalaharris because she fights for the rights and causes I believe need a warrior to champion them. I think she is a steady-handed, gifted leader and I believe we can accomplish so much more in this country if we are led by calm and not chaos.”

Swift also voiced her support for Walz, the Minnesota governor tapped to be Harris’ vice presidential running mate, noting how he “has been standing up for LGBTQ+ rights, IVF, and a woman’s right to her own body for decades.”

The artist signed off as “Childless Cat Lady” to end her post, which accompanied a photo of Swift holding a cat, echoing 2021 comments from Trump’s running mate, Sen. JD Vance of Ohio, that recently surfaced. In a 2021 interview, Vance lamented that the country was being run by “a bunch of childless cat ladies who are miserable at their own lives.” Vance later said he was being sarcastic.

Swift acknowledged the post that Trump had recently shared AI-generated images to his Truth Social account that showed women wearing “Swifties for Trump” t-shirts and falsely suggested she had endorsed him. They included a satirical post that claimed fans of Swift were “turning to Trump” after security concerns led to the cancellation of her concerts in Vienna in August.

“I accept!” Trump wrote when he posted the false images.

Swift said the incident triggered her “fears around AI, and and the dangers of spreading misinformation.”

“It brought me to the conclusion that I need to be very transparent about my actual plans for this election as a voter,” she said. “The simplest way to combat misinformation is with the truth.”

While it’s unclear what or any impact Swift’s endorsement could have, her Instagram post drove 405,999 users to visit the site vote.gov over the course of the following day.

The Harris-Walz campaign reacted to the Truth Social post with a statement cleverly titled “Trump’s Bad Week (Taylor’s Version),” which referenced 28 of Swift’s songs.

“We’re pretty sure it’s Safe (& Sound) to say Donald Trump’s week has him Down Bad,” the statement read. “Mr. Not-at-all Fine has spent this week working through his feelings, whining about his Champagne Problems, and spending exactly none of his time addressing the issues facing the American people.”

The campaign went on to slam the former president using references to 28 of Swift’s songs, with lines like “Call it What You Want, but it’s Nothing New for the Smallest Man Who Ever Lived.”