Romney is neither dumb nor corrupt. But he does suffer from intense jealousy of Trump since Trump said his Gucci store is worth more than Romney. Jealousy is one of the strongest human emotion.
I'd concur. There is no other way to logically explain his strident opposition to Trump, especially after Trump backed him in 2012.
Some Mormon haters on this forum try to blame religion, but Mormon voters are the most conservative voting demographic in the country. Mitt was the beneficiary of some of that tribal vote (Harry Reid, too), but neither is a conservative.