Beto O’Rourke’s animated speaking style on Thursday caught the attention of the man he hopes to unseat, as President Donald Trump wondered if the Democrat is “crazy.”

Former Texas congressman O’Rourke became the latest Democrat to throw his hat in the ring of presidential contenders, announcing his decision in a video. In it, the 46-year-old gestures frequently to make his points, including that the U.S. needs to “squarely confront the challenge of climate change, before it’s too late.”