Minnesota Gov. Tim Walz (D) hit back pointedly at Donald Trump on Thursday, responding to the president’s latest online attack against him with a four-word challenge: “Release the MRI results.” Trump used an offensive slur to describe the 2024 Democratic vice presidential nominee during a furious Truth Social rant about immigration . In his tirade, Trump said Walz was “seriously retarded” and accused him of doing “nothing, either through fear, incompetence, or both” to stop what he falsely