Donald Trump Jr. received a letter accompanied by an unidentified “white powder” at his residence on Monday, triggering a police response, a new report shows. According to The Daily Beast, three sources said “Multiple fire trucks and men in hazmat suits were spotted outside Donald Trump Jr.’s home in Jupiter, Florida, on Monday evening.” As of press time, it is not clear whether the substance poses a hazard, but a source told Maggie Haberman it is not believed to be lethal. However, many such attacks, generally false alarms, have been made against politicians and public figures over the years,…