The prospects for a safe future for the United States would be "greatly diminished" should Donald Trump become president, Mitt Romney said.
Romney, in a blistering speech at the University of Utah in Salt Lake City, slammed Trump as "a phony" and "a fraud" who is "playing the American public for suckers."
"His promises are as worthless as a degree from Trump University," Romney said.
"His domestic policies would lead to recession," Romney said of Trump. "His foreign policies would make America and the world less safe. He has neither the temperament nor the judgment to be president. And his personal qualities would mean that America would cease to be a shining city on a hill."
"His imagination must not be married to real power," Romney said.