Trump attorney, Supreme Court justice clash on whether a president who 'ordered' a 'coup' could be prosecuted

An attorney for former President Donald Trump in the presidential immunity hearing clashed with Supreme Court Justice Elena Kagan over a hypothetical question on whether a president who "ordered" a "coup" could be prosecuted. 

"If it's an official act, there needs to be impeachment and conviction beforehand," Trump's attorney John Sauer argued Thursday before the Supreme Court, which is being broadcast publicly via audio only. 

Sauer's statement was in response to Justice Elena Kagan's hypothetical question, asking if a president who is no longer in office directing the military to stage a coup would constitute an "official act."