"The Greatest Witch Hunt in the history of our Country!" the president tweeted Monday. Trump went so far as to suggest that Adam Schiff, the Californian lawmaker heading the impeachment inquiry, be arrested for treason. Schiff opened a congressional hearing last week with a parody imitation of Trump speaking like a mob boss to pressure Ukrainian President Volodymyr Zelensky to investigate his potential 2020 White House opponent Joe Biden.
A whistleblower complaint about Trump's July 25 phone call with the Ukrainian leader has led to the opening of the impeachment inquiry in the House. If Trump is impeached by a simple majority vote in the 435-member House he would face a trial in the Republican-led Senate, where a two-thirds majority would be needed to convict him and remove him from office.
Schiff's impersonation was intended to dramatize his contention that the president was acting like a mafia boss but it has been widely criticized by conservative media.
"It bore NO relationship to what I said on the call," Trump said of Schiff's remarks. "Arrest for Treason?" Trump also raised eyebrows by retweeting comments made by a Baptist pastor, Robert Jeffress, to Fox News in which he warned of the dangers of "civil war" if the president was impeached.
"If the Democrats are successful in removing the President from office (which they will never be), it will cause a Civil War like fracture in this Nation from which our Country will never heal," Trump paraphrased Jeffress as saying.
That tweet by the president drew condemnation from at least one Republican lawmaker, Representative Adam Kinzinger of Illinois. "I have visited nations ravaged by civil war," Kinzinger tweeted. "@realDonaldTrump I have never imagined such a quote to be repeated by a President. This is beyond repugnant."
Trump's mention of civil war also drew criticism from Richard Painter, who served as White House chief ethics lawyer under president George W. Bush.
"A president who threatens civil war if the political process does not support him cannot be allowed to command the United States military," said Painter, who has left the Republican Party. "He should be removed from office immediately."
Trump has revived various conspiracy theories including one that posits that the hacking of a Democratic Party server and theft of emails during the 2016 presidential election came from Ukraine and not from Russia.
"It is completely debunked," Trump's former Homeland Security adviser Thomas Bossert, told the ABC's "This Week," of the conspiracy theory.
During his call with Zelensky, Trump asked Ukraine's leader to look into this along with a probe of Biden and his son Hunter, who served on the board of a Ukrainian gas company.
Besides Democrats, Trump has stepped up his attacks on one of his favorite targets - the media.
"These Radical Left, Do Nothing Democrats, are doing great harm to our Country," Trump tweeted. "They are lying & cheating like never before in our Country's history in order to destabilize the United States of America & it's upcoming 2020 Election.