CNN  — 

Republican senators are dismissing the scathing criticism leveled against President Donald Trump by his former defense secretary, James Mattis, the latest sign that Republicans by and large are showing unwavering support for the leader of their party during this high-stakes election year.

Mattis, who has widespread support among Senate Republicans for his long military service to the country, contended that Trump “does not even pretend to try” to unite the country and is instead engaged in a “deliberate effort” to divide the country, while lacking “mature leadership.” Mattis excoriated Trump’s decision to hold a photo-op Monday at a church near the White House, saying troops were ordered to “violate the Constitutional rights of their fellow citizens” who were protesting but were cleared out by police with force to make way for the President’s visit.

The criticism, however, was met with a shrug of the shoulders by several senior Republicans on Thursday.

“It’s Gen. Mattis’ opinion, he’s free to express it,” Sen. Ron Johnson, chairman of the Homeland Security and Governmental Affairs Committee, told CNN. Asked again if he agreed with any of the criticism, Johnson said: “All I’m going to say about Gen. Mattis is I do respect him. He’s a great American. It’s his opinion to express it.”

Johnson also would not weigh in on how the Monday event took place, contending “I still haven’t seen any footage of how the crowd was cleared out.”

Leaving the floor on Thursday morning, Senate Majority Leader Mitch McConnell was silent when asked twice about Mattis’ criticism, returning to his office and ignoring a reporter’s questions.

The reaction reflects how many top Republicans on Capitol Hill have calculated that their fortunes in the 2020 elections rest in large part on Trump’s performance at the polls – and a messy, internecine war with a President with an itchy Twitter finger would amount to a fruitless and damaging endeavor.

The lone senator to break ranks: Sen. Lisa Murkowski of Alaska, who is up for reelection in 2022, told CNN she agrees with the criticism and later told reporters she is “struggling” about whether to endorse Trump in 2020.

Trump tweeted on Thursday night that he will campaign against the senator when she is up for reelection in two years and that he will endorse any candidate, “good or bad.” Murkowski lost her party’s nomination and, subsequently, GOP leadership’s support in 2010, but she still won reelection that year via a write-in campaign.

Others either defended Trump or contended they didn’t want to get involved in the dispute.

Asked about the direct repudiation of Trump’s leadership leveled by Mattis, Sen. Thom Tillis said: “They’ve got a little bit of a history on disagreements. So I’m not going to get between a squabble between a former secretary I have tremendous respect for and a president. That’s something for them to settle.”

Tillis, a North Carolina Republican who is up for re-election, also wouldn’t say whether he has any concerns with the way the Monday photo-op was handled, something that Mattis cited in his criticism.

“I’m not going to comment on that,” Tillis said, citing reports of protesters throwing frozen water bottles, though most of the protesters were acting peacefully and were met with force by the police, according to multiple reports. “This is another example where this is a cauldron and we gotta figure out a way to lower the temperature.”

Senate Judiciary Chairman Lindsey Graham, who also faces voters in the fall, said that while Mattis is “an American hero” and has “every right to criticize President Trump,” he added: “I think he’s missing a lot here.”

“It’s just politically fashionable to blame Trump for everything – and I’m not buying it,” Graham, a South Carolina Republican, told CNN about Mattis’ criticism. “And he jumped into politics – Gen. Mattis did. And I think he’s missing a lot about what’s going on in America politically.”

Graham, though, still questioned the need for Trump to hold the Monday photo-op in front of the church while holding up the Bible. The White House argued Trump was showing strength after a fire was set on the property the night before.

“I never understood,” Graham said about the Monday event. “Going over to visit church is fine. But waving the Bible – I don’t know what that was all about.”

Some Republicans said Mattis’ criticism was misplaced.

Sen. John Cornyn, a Texas Republican up for reelection, said of Mattis: “By just blaming the President, he’s only looking at half the equation.”

Sen. Todd Young of Indiana, chairman of the National Republican Senatorial Committee, said the criticism was “between the United States and his former secretary of defense.”

“I’m focused on real threats to freedom,” Young said, adding of Mattis: “If anyone can understand that, a fellow Marine can.” He didn’t respond to a question about Mattis citing Trump as a threat to freedom.

Sen. James Lankford of Oklahoma, who was critical of the Monday event after it occurred and then was singled out by Trump on Twitter, seemed to temper his criticism on Thursday, saying “the longer we go on, the more questions there are on how it started out.” Lankford said that it could have been “reasonable” to use force if the protesters were being violent, citing statements made by the US Park Police, especially since violence occurred the night before.

“We don’t know yet,” Lankford said when asked if force against protesters could have been justified Monday evening. “So let’s get the facts out on it.”

Asked about the criticism from Mattis that Trump is purposefully dividing the country, Lankford said: “What’s interesting is when I go back 10 years, that was the same criticism I was hearing about President [Barack] Obama at this time – that they were saying he was dividing the country.”

Sen. John Kennedy, a Louisiana Republican, also urged the President to “ignore the criticism in politics” when asked about the Mattis comments.

“I don’t know that him saying this is especially helpful to the various crises that we’re going through right now,” Kennedy told reporters Thursday when asked about the former defense secretary. “But if he feels the need to express himself he can.”

Even close Mattis allies were wary about endorsing his criticism.

Senate Armed Services Chairman James Inhofe said Mattis “has been a hero of mine for a long time” and is “the greatest marine in the world.”

But the Oklahoma Republican added: “He’s never had the communication background to take the job that he initially had three years ago with the President. And so his communication is not as cautious as it should be in that job, and of course what he said was damaging.” Asked if he agreed with the criticism that Trump is trying to purposefully divide the country, Inhofe said: “No.”

Even some Trump critics were cautious.

Sen. Mitt Romney of Utah, the lone Republican who voted to remove Trump from office over abuse of power charges, praised the former defense secretary “as a person of extraordinary integrity and sacrifice. He’s a patriot, who has sound judgment and capacity. I admire him a great deal.”

But when asked if he agreed with Mattis’ criticism, Romney walked away.

This story has been updated with additional developments Thursday.

CNN’s Cat Gloria contributed to this report.