'Mitt Romney is a stiff': Donald Trump launches flurry of attacks before Romney's big speech

Donald Trump repeatedly attacked Mitt Romney on Thursday ahead of the speech in which Romney is expected to torch the Republican presidential frontrunner.

"Mitt Romney is a stiff. Mitt Romney will not get elected. Mitt Romney failed twice and really failed last time," Trump said on NBC's "Today" show, referring to Romney's two past presidential bids.

Romney is set to address the 2016 race later in the day at the University of Utah.

According to excerpts of Romney's speech leaked Thursday morning, the GOP's 2012 presidential nominee will declare Trump as utterly unelectable compared to his primary rivals.

"Donald Trump is a phony, a fraud. His promises are as worthless as a degree from Trump University. He's playing the American public for suckers," Romney will reportedly say.

"His domestic policies would lead to recession. His foreign policies would make America and the world less safe. He has neither the temperament nor the judgment to be president," he'll add.

In his whirlwind of Thursday-morning interviews and tweets attacking Romney, Trump reminded the public that Romney sought his endorsement four years ago.

"He begged me four years ago for my endorsement - I mean, literally begged me," Trump said on the "Today" show. "And he's a failed candidate. I mean, frankly, I backed him; he failed. He was a horrible candidate, didn't know what he was doing."

On ABC's "Good Morning America," Trump added: "Mitt Romney was a failed candidate - should have beaten Barack Obama easily." On MSNBC's "Morning Joe," Trump again stressed that Romney "begged" for his endorsement during the 2012 race.

As is his wont, Trump also repeatedly attacked Romney on Twitter: