Special counsel Robert Mueller floated the idea of a subpoena to force President Donald Trump to answer questions after his lawyers said Trump had no obligation to cooperate with Mueller's investigation, the Washington Post reported late Tuesday. The tense incident in March is believed to be the first time Mueller raised the possibility of subpoenaing Trump to testify before a grand jury, the Post said. The faceoff reportedly led to John Down stepping down from Trump's legal team over a disagreement on whether Trump should submit to the interview, and also led to Mueller's team providing Trump's lawyers almost 50 questions about what they were seeking. The New York Times published those questions Monday.