Harvard law professor: Trump's 'civil war' threat is 'independent basis' for impeachment
Donald Trump speaks on The White House lawn (MSNBC/screen grab)

President Donald Trump may have added another count to his articles of impeachment by threatening "civil war."

In a tweet on Monday, Trump quoted pastor Robert Jeffress: "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's tweet is grounds for impeachment, according to Harvard Law Professor John Coates.

"This tweet is itself an independent basis for impeachment - a sitting president threatening civil war if Congress exercises its constitutionally authorized power," he wrote.

Democrats have not said if Trump's threat will be folded into their impeachment inquiry.