Mitt Romney is now the lone GOP voice willing to stand up to Trump

(CNN) GOP Sen. Mitt Romney of Utah may be one of the starkest reminders in the US Senate right now about just how much the Republican Party has changed in eight years.

Once the party's standard bearer and presidential nominee, Romney has found himself in a moment where he is a man on an island, often one of the GOP's only members criticizing President Donald Trump publicly for his tone , his tweets and his inability to unite the country at a time of racial reckoning.

But in the wake of the death of George Floyd and the outpouring of calls for police reform and equal justice, Romney has seemed more incapable than ever of toeing the party line or staying quiet. Over the weekend, Romney marched alongside protesters in Washington , tweeting what he has said is an obvious and important phrase to repeat: "Black lives matter." In recent days, the senator has refused to say if he will support Trump for reelection in November.

Romney credits his father's legacy as the governor of Michigan in the late 1960s for some of his recent actions, but also says the events of the last several weeks have left him thinking -- like a lot of Americans-- that more needs to change.

"I state the obvious, which is black lives matter," Romney told reporters Monday evening in a wide-ranging interview. "If there is injustice, we want to correct that. If there is prejudice, we want to change that. If there is bias, we hope to give people a different perspective."

Romney said while he doesn't view the issue of equality through a political lens, there is no denying his party has an "embarrassingly small share of African American votes."

In the last several weeks, Romney's small acts of defiance against the President's words or tweets have been about more than just a reaction to Floyd's death.

In May, Romney said during a hearing on coronavirus that he found the US record on testing -- something Trump repeatedly boasted about -- "nothing to celebrate whatsoever."

After Trump repeatedly raised a conspiracy theory about the death of an aide who once worked for former congressman now MSNBC host Joe Scarborough, Romney tweeted "enough already" last month. And when Trump tweeted Tuesday about an unsubstantiated report that a protester who had been knocked down by police in Buffalo, New York, was a member of Antifa, Romney went to the mics and told reporters on Capitol Hill that the tweet was "shocking" even as most of his Republican colleagues refused to stop or to listen to the tweet be read to them.

"I saw the tweet. It was a shocking thing to say and I won't dignify it with any further comment," Romney said.

Lawmakers and aides close to the senator argue that his recent statements aren't new or escalating. They say the junior senator from Utah has always vowed to speak out against the President's actions when he doesn't agree. He, after all, was one of Trump's staunchest critics in 2016.

"Everyone should be allowed to speak their mind," Republican Sen. Shelley Moore Capito of West Virginia told CNN about Romney. "I think Mitt has a lot of good friends within our conference. ... While it might be hard externally for people to think that if he says things that you don't agree with or he maybe says it the wrong way ... we still have respect for his years of his service and his vision."

Romney's face-offs with Trump have come in many forms over the years, from blistering speeches to heated op-eds, including one he published in 2019 in The Washington Post where he argued that "the president [had] not risen to the mantle of the office." Romney frustrated his GOP colleagues in February when he crossed the aisle and joined Democrats in a vote to remove Trump from office amid the impeachment trial. Republicans blasted Romney for stepping on the messaging of Trump's inevitable acquittal and not giving them a heads up.

"I'll give him this: professional rollout," one GOP senator told CNN at the time . "Not very collegial, but very professional."

In recent days, Romney has said he is working with colleagues to help craft legislation to rein in police brutality. And while many Republicans did not want to comment on his criticism of Trump, they did argue that Romney has emerged as a legislative partner.

"He is willing to engage on important issues that impact the country," said Sen. Tim Scott, a Republican from South Carolina who's leading efforts to overhaul policing. "We should welcome every single senator who wants to be part of the solution. That is good news. I think self-awareness is a good thing as well, but he is trying to make a difference, and I think that should be admired."