Washington, United States (AFP)— Republican Senator Mitt Romney said Tuesday that the world is watching the “vile” US political scene with “horror” and attacked President Donald Trump’s behavior ahead of the election.

“It is time to lower the heat,” said Romney, one of the few prominent Republicans to have frequently criticized Trump since his 2016 election win.

The Utah senator lashed out at Trump, but also his opponents on the left, for shifting the nature of politics “from spirited debate to a vile, vituperative, hate-filled morass that is unbecoming of any free nation — let alone the birthplace of modern democracy.”

Romney, the only member of the Republican Senate majority to vote for Trump’s impeachment conviction in February, homed in on the president’s calling Democratic vice presidential candidate Kamala Harris a “monster” and the Democratic leader of the House Nancy Pelosi “crazy.”

While Romney also criticised “blistering attacks” by Democrats, he took the unusual step three weeks out from the presidential election of highlighting what he said was Biden’s refusal “to stoop as low as others.”

Romney’s statement went after media organizations which he said “amplify” the brutal political fighting.

And referring to a failed plot to kidnap the Democratic governor of Michigan — herself a frequent target of Trump’s violent criticism — he warned that “rabid attacks kindle the conspiracy mongers and the haters.”

“The world is watching America with abject horror,” said Romney, who lost the 2012 election to Barack Obama.

“Many Americans are frightened for our country — so divided, so angry, so mean, so violent.”

“The consequence of the crescendo of anger leads to a very bad place. No sane person can want that,” he said.