Upon closer examination of their records, they seem virtually identical.
When, ever, has Romney insisted on leveling the playing field in China's economic war against the USA.
When, ever, has Romney insisted on "making legal immigration difficult, and making illegal immigration impossible"?
When, ever, has Romney insisted on reviving the manufacturing base of the USA, drilling in the USA for oil and gas, reducing the monstrosity of government so that small businesses and individuals can once again prosper in the USA?
I have no idea. I'm not an expert on Mitt Romney. BUT, I have never heard Donald Trump talk about ANY of these issues either, before the last several weeks. So, you'll forgive me if I'm skeptical about his current positions on these topics as well.
I do however, remember reading a quote from Trump saying that he thought Obama could be the best president ever. I'm not aware of any of the current GOP candidates, including Romney, ever make such a claim.