(CNN) The story of Mitt Romney and Donald Trump is long and complicated. And over the weekend, it added a new chapter.

In a Salt Lake Tribune op-ed headlined, " Where I stand on the Trump agenda ," Romney, the front-runner for the seat that will be left vacant by Republican Sen. Orrin Hatch's retirement, made clear that if elected he would not walk in lockstep with Trump. Writes Romney:

"On one hand there are those who believe supporting the Trump agenda means supporting every policy the president proposes, whether or not they actually agree with that policy. It means refraining from criticizing anything the president says or does. The argument for this position is that you pick a team, so to speak, and when the leader of the team is criticized, his or her power to act is weakened and the opposition helped. So in order to achieve Republican policy aims, solid Republicans should stand with the president 100 percent, or at least stay silent when in disagreement.

"I take a different course. I will support the president's policies when I believe they are in the best interest of Utah and the nation."

It's impossible to separate that view from the recent political context as well as Romney's fraught relationship with Trump.

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