It appears you’re referring to a hypothetical situation. There has been considerable media coverage regarding Taylor Swift’s political endorsements and President Trump’s reactions, but as of my latest updates, there is no record of Trump posting ‘I hate Taylor Swift’.
Please note that while Trump expressed disagreement with Swift’s political views several times, it’s important to check the credibility of sources. Currently, I’m not updated in real-time, so it is advisable to verify from a trustworthy news source for real-time updates.