The grand jury investigating alleged collusion between Russia and Donald Trump's presidential campaign has sent a witness a subpoena seeking all documents involving the president and a host of his closest advisers, according to a copy of the subpoena reviewed by NBC News. According to the subpoena, which was sent to a witness by special counsel Robert Mueller, investigators want emails, text messages, work papers, telephone logs and other documents going back to Nov. 1, 2015, 4½ months after Trump launched his campaign.