Mitt Romney is a serious political threat to President Donald Trump.

That explains why Trump, in defiance of his change-agent brand, is encouraging Sen. Orrin Hatch to run for an eighth term — which could block Romney’s path to the Senate. The potential danger posed by Romney is why Trump is choosing kind words the failed 2012 presidential hopeful. And it’s why some Republicans think Romney ought to throw caution and courtesy to the wind and run whether or not Hatch does.

“All the old lanes and rules and mores and norms have just been blown apart because of Trump. You end up in a situation where the last person playing by the rules loses,” said Rick Wilson, a Florida-based GOP strategist and major Trump critic. “Mitt Romney should consider running for the seat.”

It’s easy to see a scenario in which Romney combines his national name-recognition and the platform of the Senate seat to become a persistent thorn in Trump’s side — a leader of the establishment wing of the Republican Party who has some credibility with conservatives, a reputation for decency, and easy access to the national media.