WASHINGTON • President Donald Trump has lashed out at the first Republican congressman to call the US leader's behaviour impeachable, while Democrats warned Mr Trump's stonewalling of congressional probes is strengthening the case for an impeachment inquiry.
Mr Trump called Republican Representative Justin Amash "a total lightweight" and "a loser" on Twitter on Sunday, a day after the Michigan conservative said the Mueller report showed that the President "engaged in specific actions and a pattern of behaviour that meet the threshold for impeachment".
Mr Amash's criticism made calls in the US Congress for Mr Trump's impeachment bipartisan, though just barely, with most Republicans still standing by the President at a time of economic growth, turbulent markets and global trade tensions.
Mr Amash cited Special Counsel Robert Mueller's 448-page report on Russian meddling in Mr Trump's favour in the 2016 election for his critical comments, saying most lawmakers have not read it.
On Twitter on Saturday, Mr Amash said the report showed Mr Trump had obstructed justice and added: "President Trump has engaged in impeachable conduct."
A frequent Trump critic, Mr Amash is a part of the House Freedom Caucus, a conservative faction. He has also signalled he would consider running as a libertarian against Mr Trump in 2020.
Counter-punching in his usual style, Mr Trump tweeted: "Never a fan of @justinamash, a total lightweight who opposes me and some of our great Republican ideas and policies just for the sake of getting his name out there through controversy ... Justin is a loser who sadly plays right into our opponents' hands!"
Mr Amash's comments echoed the conclusions of many Democrats.
House of Representatives Speaker Nancy Pelosi has said Mr Trump was moving closer to impeachment with his stonewalling of numerous congressional investigations of him and his presidency.
House Intelligence Committee chairman Adam Schiff, one of six committee chairs leading probes of Mr Trump, also said the case for impeachment is being strengthened by White House stonewalling.
"If the only way that we can do our oversight is through an impeachment proceeding, then maybe we have to go down that road," Mr Schiff told CBS' Face the Nation programme.
Still, Democrats are divided about impeachment. With the 2020 election campaign heating up, Ms Pelosi said impeachment proceedings would be "divisive".
No US president has ever been removed from office as a direct result of the US Constitution's impeachment process.
The Mueller report, now at the centre of an escalating oversight battle between Mr Trump and House Democrats, detailed extensive contacts between Mr Trump's 2016 campaign and Russia, but did not find that there was a conspiracy with Moscow. The report also described actions Mr Trump took to try to impede Mr Mueller's investigation, but made no formal finding on the question of obstruction, leaving the matter to Congress.