In an extraordinary public showdown, President Donald Trump fired the acting attorney general of the United States after she publicly questioned the constitutionality of his refugee and immigration ban and refused to defend it in court. The clash Monday night between Trump and Sally Yates, a career prosecutor and Democratic appointee, laid bare the growing discord and dissent surrounding an executive order that halted the entire U.S. refugee program and banned all entries from seven Muslim-majority nations for 90 days.