As a person with good lawyers and experience being investigated, Trump would undoubtedly claim these comments were nothing more than First-Amendment-protected political speech if he were charged with encouraging the mob to commit seditious conspiracy. But that might not help. In 1969, the U.S. Supreme Court, in Brandenberg v Ohio, found that the government can punish inflammatory speech when it is “directed to inciting or producing imminent lawless action and is likely to incite or produce such action.”
Trump passes the test. As his statements make clear, he brought the members of the mob to D.C. He convened them at a rally; he and others inflamed the audience with lies about a stolen election and their duty to save the country from the certification that was underway at that moment. He pointed them at the Capitol and persuaded them to “do something about it.” He offered to go with them. He had every reason to believe his rhetoric would lead to violence in the same way it did at his rally on December 12.
Trump could also have a bigger problem. If the federal murder probe into Officer Sicknick’s death determines that those responsible were incited to violence at the Save America rally just hours before, Trump could find himself charged with inciting a murder. Proving the president intended to incite the crowd to commit murder would be a long shot bordering on impossible. But the mere fact that we are discussing this remote possibility is a sad statement about the state of this presidency.