"Mitt Romney's extensive resume has many Republicans looking to him to take on a role in the Senate as a political and moral counterweight to a president many in the GOP see as divisive and undignified," AP's Matthew Daly writes.

Why it matters: "If he does go after Trump, Romney will find himself among a dwindling breed in Congress."

The backdrop:

• "The 2012 GOP nominee for president announced Friday he is running for the Utah Senate seat being vacated by GOP Sen. Orrin Hatch."
• "Romney, 70, [has been] one of his party's fiercest critics of President Donald Trump."
• Trump said in 2016 that Romney "choked like a dog."