Senator-elect Mitt Romney’s biting critique that President Trump “has not risen to the mantle of the office” touched off a series of counterattacks from Mr. Trump’s allies Wednesday and an initial effort to insulate him from a primary challenge next year, an illustration of the loyalty Mr. Trump still commands even as he enters a perilous stretch of his presidency.
Mr. Trump himself wasted little time in rebuking Mr. Romney for an opinion piece in the Washington Post, pointedly noting that the former Massachusetts governor lost his 2012 presidential bid. “I won big, and he didn’t,” the president tweeted on Wednesday morning. “He should be happy for all Republicans. Be a TEAM player & WIN!”
Here we go with Mitt Romney, but so fast! Question will be, is he a Flake? I hope not. Would much prefer that Mitt focus on Border Security and so many other things where he can be helpful. I won big, and he didn’t. He should be happy for all Republicans. Be a TEAM player & WIN!
— Donald J. Trump (@realDonaldTrump) January 2, 2019
But Mr. Trump’s loyalists responded even more ferociously, and out in front was Ronna McDaniel, the chairwoman of the Republican National Committee who is also Mr. Romney’s niece. She often went by her maiden name, Romney, until Mr. Trump suggested she change it.
“For an incoming Republican freshman senator to attack @realdonaldtrump as their first act feeds into what the Democrats and media want and is disappointing and unproductive,” Ms. McDaniel wrote about her uncle on Twitter.
Mr. Romney’s broadside, published just before he is to be sworn in as the junior senator from his current home state of Utah, represented the latest turn in an on-and-off political feud between the two men that dates back to Mr. Romney’s attacks on Mr. Trump during the 2016 campaign. And it amounted to a blunt reminder to Mr. Trump that one of his most outspoken Republican critics would soon have a high-profile platform in Washington — at a moment when series of investigations have engulfed the White House and Democrats are about to take control of the House.
Sensing the makings of a primary threat to the president, some of his most ardent backers on the R.N.C. began making the case that the party’s rules be changed to ensure Mr. Trump’s renomination in 2020.
Calling Mr. Romney’s attack “calculated political treachery,” Jevon Williams, the national committeeman from the Virgin Islands, wrote in an email to other members of the Republican National Committee that the party should move to protect Mr. Trump by amending party rules to make it harder for a challenger to have his named place in nomination at the G.O.P.’s 2020 convention.
And, Mr. Williams wrote, the party should use its winter meeting this month to pass a resolution endorsing Mr. Trump and declaring him “the presumptive nominee in 2020.”
And other Republicans saw Mr. Romney’s offensive as an opening to nurture their ties with Mr. Trump, who keeps close tabs on who defends him in the media. Senator Rand Paul of Kentucky, who has been aggressively lobbying the president to side with his non-interventionist approach to foreign policy, scheduled an afternoon conference call with reporters to go after his soon-to-be colleague.
Mr. Trump’s senior aides were less exercised about Mr. Romney’s attack, with one of them noting with pleasure that the president was relatively restrained in his tweet about Mr. Romney — and that an overreaction would only reinforce Mr. Romney’s criticism. The Trump aides gamely described his tweet about Mr. Romney as tame compared to what they expected from him, suggesting the president is still preoccupied with the fight over funding a border wall.
But White House officials were still irritated with Mr. Romney, pointedly noting that they only got a brief head’s up that the essay was coming. Ms. McDaniel informed them about the piece, according to a senior White House aide.
Mr. Trump has been warily eying the arrival of Mr. Romney since well before The Post published the piece online Tuesday night.
Last fall, Mr. Trump, mindful that Mr. Romney would move quickly to assert himself, asked Senator Mitch McConnell, the majority leader, not to give Mr. Romney a leadership platform. A Republican familiar with the discussion said Mr. Trump specifically wanted to keep Mr. Romney away from the National Republican Senatorial Committee, the party’s campaign arm in Senate races.
But even if Mr. Romney gets no formal title with Senate Republicans, Trump aides worry that Mr. Romney’s extensive fundraising network will make it hard for the G.O.P. campaign committee to resist making use of him in the 2020 Senate election cycle.
The notion of installing Mr. Romney at the campaign committee was a pet project of his longtime family friend and adviser, Spencer Zwick, who raised the idea with donors as a way of carving out a leadership role as an unusually prominent freshman lawmaker.
The idea drew at least mild interest from Mr. Romney’s wife, Ann, but Mr. Romney was less intrigued and viewed it as a nonstarter for practical reasons, two people briefed on the conversations said. The position is effectively a fund-raising assignment, and another senator, Todd Young of Indiana, got the job. Mr. Young told Republican officials last month that there had been conversations about getting Mr. Romney involved with the campaign committee, according to a G.O.P. strategist familiar with the conversations.
But operating in a formal capacity as a partisan functionary would likely have required Mr. Romney to stay silent about his disagreements with Mr. Trump, lest he put Republican candidates in the position of having to pick sides between the two men — the sitting president and the best-known Republican senator — on a routine basis. Republican leaders believe that scenario may come to pass even without giving Mr. Romney an official leadership role, as he discovers the enormous megaphone available to him in the halls of Capitol Hill.
And Mr. Romney, his associates say, remains viscerally uneasy with Mr. Trump and unhappy with the recent tumult in his administration. An avowed national security hawk, Mr. Romney was alarmed by the abrupt departure of Jim Mattis, the former defense secretary, late last month, and also troubled by the ouster of John F. Kelly as the White House chief of staff, a person close to Mr. Romney said.
But it remains unclear if Mr. Romney will now mute his criticism, particularly if Mr. Trump continues to resist a more pointed personal response.
“Will this be part of broader, and more sustained effort in which senators and House members pressure the White House to chart a new course and change their behavior?” asked Kevin Madden, a Republican strategist who worked on Mr. Romney’s campaign, noting that the governor-turned-senator’s blistering speech against Mr. Trump in 2016 was not followed by any plan to derail his candidacy.
“Speeches and op-eds are one thing,” Mr. Madden said. “But a broader, more sustained strategy is what would make an impact.”