situation that you could see where don mcgahn is charged with perjury? you seem to be contradicting what he is saying. >> i don't want to talk about that now. >> reporter: the president has been busy beating back another member of his party, justin amash, the first republican congressman to accuse mr. trump of impeachable offenses, who started this tweet storm over the weekend, first tweeting, mueller's report reveals that president trump engaged in specific actions and a pattern of behavior that meet the threshold for impeachment. then doubling down today. they say obstruction of justice requires an underlying crime. in fact, obstruction of justice does not require the prosecution of an underlying crime. the president fired back, tweeting that he was, quote, never a fan of justin amash, a total lightweight. justin is a loser, who sadly plays right into our opponent's hands. gop leaders are backing mr. trump. >> now, you've got to understand justin amash. he's been in congress quite some time. i think he's only ever asked one question in all the committee he's been in.