SALT LAKE CITY, UT (CBS News) - Just hours before Thursday night's GOP debate, 2012 Republican Presidential Nominee Mitt Romney called GOP front-runner Donald Trump a "phony" and a "fraud."
Romney spoke from the University of Utah in Salt Lake City on his take on the 2016 presidential race, a far cry from four years ago, when Romney was delighted to receive Trump's endorsement.
"Back in 1964, just days before the presidential election, which, incidentally, we lost, Ronald Reagan went on national television and challenged America, saying it was a 'time for choosing,'" Romney said. "He saw two paths for America: one that embraced conservative principles dedicated to lifting people out of poverty and helping create opportunity for all; and the other, an oppressive government that would lead America down a darker, less-free path. I'm no Ronald Reagan, and this is a different moment in time. But I believe with all my heart and soul that we face another time for choosing, one that will have profound consequences for the Republican Party and, more importantly, for our country."
Romney said the billionaire businessman's "promises are as worthless as a degree from Trump University."
"So even though Donald Trump has offered very few specific economic plans, what little he has said is enough to know he would be very bad for American workers and for American families," Romney said. "But you say, 'Wait, wait wait. Isn't he a huge business success? Doesn't he know what he's talking about?' No, he isn't. And no, he doesn't. Look, his bankruptcies have crushed small businesses and the men and women who worked for them.
Romney said he inherited his business, he didn't create it.
"A business genius he is not," Romney said. "Now Donald Trump tells us that he is very, very smart. I'm afraid when it comes to foreign policy, he is very, very not smart."
Trump, in turn, dismissed Romney as "a stiff" who "didn't know what he was doing" as the party's candidate in 2012 and blew a chance to beat President Barack Obama.
"People are energized by what I'm saying" in the campaign and turning out in remarkable numbers to vote, Trump told NBC's "Today."
Romney's associates say he has watched Trump's ascent with alarm and feels the need to "shake some sense" into voters who are considering the real estate mogul.
Katie Packer now runs an anti-Trump PAC after serving as Romney's 2012 deputy campaign manager.
"I think what he wants to do is sort of be the adult in the room and sort of say 'enough,'" Packer said.
The speech came amid open panic in the party establishment and is not expected to mince words. So far, none of Romney's attacks have worked, including calls to release Trump's tax returns.