Trump's social media posts sparked a chain of threats, with Democratic lawmakers demanding police investigate the president

The office of Representative Jason Crow, a Democrat, is seeking an investigation by the US Capitol Police into Mr. Trump over what they describe as "intimidating, threatening and alarming" posts from social media. It is rare for members of Congress to ask the police to investigate a sitting US president. Crow's request is a slim attempt to touch on the vague and long-contentious legal question of how much the president is subject to the normal procedures of the criminal justice system. Mr. Trump has previously made posts calling Democratic lawmakers "traitors", calling for "their arrest and trial" and declaring "lock them up", as well as writing that "sedition is punishable by death". "Following these messages from the president, there has been a significant increase in the number of calls and emails to our congressional offices containing violent statements and additional threats," Crow said.