Donald J. Trump signed autographs after his rally in Billings, Mont., on Thursday.CreditStephen Crowley/The New York Times

BISMARCK, N.D. — A constant stream of changes and scuffles are unsettling Donald J. Trump’s campaign team, including the abrupt dismissal this week of his national political director.

A sense of paranoia is growing among his campaign staff members, including some who have told associates they believe that their Trump Tower offices in New York may be bugged, according to three people briefed on the conversations.

And there is confusion among his donors, who want to give money to a “super PAC” supporting Mr. Trump, but have received conflicting signals from top aides about which one to support.

On Thursday, Mr. Trump secured the Republican Party’s nomination for president, a remarkable achievement for a political newcomer. But inside his campaign, the limits of his managerial style — reliant on his gut and built around his unpredictable personality — are vividly on display, according to interviews with nearly a dozen Republicans inside and outside of the operation.

Two months after assurances that the candidate would become “more presidential” and transition to a more unifying phase of his campaign, Mr. Trump continues to act as if the primary is still underway. His team has struggled to fill top positions, such as communications director, and Mr. Trump has made clear he still sees himself as his own chief adviser.

This week, Mr. Trump fired Rick Wiley, his national political director, after Mr. Wiley clashed with campaign officials in three states. And while fights among aides are not unusual, the daily leaks of damaging information from his campaign are prompting worry among Republican officials.

Corey Lewandoski, Mr. Trump’s campaign manager, in Billings on Thursday.CreditStephen Crowley/The New York Times

“Candidate Trump needs to better understand that he is now the titular head of the G.O.P.,” said Scott W. Reed, senior political strategist for the U.S. Chamber of Commerce. “His words and actions will have an impact on the over 6,000 G.O.P. candidates running for office — from federal races down to the courthouse.”

Asked for comment about his management style, and the current state of his campaign, Mr. Trump declined, criticizing the reporters writing this article. “You two wouldn’t know how to write a good story about me if you tried — dream on,” Mr. Trump said in an email relayed by his spokeswoman, Hope Hicks.

So far, Mr. Trump has shown little inclination to adjust to a political world. His penchant for setting up competition and infusing tension between his subordinates has carried over from his real estate company.

“He certainly does love playing people against each other, but in my experience he knew how to make me reach my potential,” said Sam Nunberg, who was fired from the campaign in 2015 after a series of clashes with the campaign manager, Corey Lewandowski. “You become very committed in that environment.”

But, as was the case with Mr. Wiley’s dismissal, Mr. Trump is reliant on information he garners himself, and can be swayed by the last person he talked to.

Mr. Trump has shown himself to be a masterly communicator, and his instincts, especially in identifying the issues that will animate voters, are shrewd. But the combat within the Trump campaign has undermined the daily messages the team seeks to promote. On Wednesday, for instance, Mr. Trump met with dozens of female chief executives and entrepreneurs before his afternoon rally in California, a meeting that was never publicized. Instead, the campaign sent out a message announcing Mr. Wiley’s dismissal.

The shake-up also hindered the campaign from pouncing on the tough day his likely Democratic rival, Hillary Clinton, was having, on the heels of aState Department inspector general’s report on her use of a private email server when she was secretary of state.

“The drama in Trumpville this week,” Mr. Reed said, totally overtook the “devastating” report, which, he added, “should be all the country is talking about.”

Now, many Republican officials worry that Mr. Trump is uninterested in transitioning into his new role, including the rigors of going up against Mrs. Clinton in a general election fight.

The Trump operation, for instance, has talked for weeks about hiring a full-time communications director, but has yet to bring anyone on board. Ms. Hicks is still the sole communications staff member. The Clinton campaign, by contrast, has a press team of more than a dozen, including people devoted solely to the news media for black and Hispanic audiences.

To complement its lean operation, the Trump campaign has begun relying on the Republican National Committee for everything from opposition research to communications help and voter data.

On Thursday, Mr. Trump expressed confidence that the R.N.C. could take over for what he has not done himself.

“They built, over years and years, staffs in every state — you can’t do that, or you can’t do it very well, if you’re doing it all over the next few months,” Mr. Trump told reporters on Thursday in North Dakota. “You can’t do that over a period of just a short while, because we have November coming up very rapidly. It’s going to be very soon.”

Yet officials in battleground states have complained for weeks that the Republican committee has not delivered the promised resources for field organizations.

Mr. Trump has also been dismissive of data analytics, suggesting in interviews that his showmanship and rallies will continue to be effective. He has suggested that he will compete in new states, despite the scant resources he has devoted to the traditional Republican map so far. And he has been adamant to aides that he intends to try to compete in New York, which no Republican has captured since Ronald Reagan, and has held discussions about hiring an additional pollster for the state.

Despite his and his aides’ talk of unification, Mr. Trump himself has so far proved unable and unwilling to rally the entire party around his candidacy. On Tuesday, he deliberately attacked Gov. Susana Martinez of New Mexico — a Hispanic rising star and head of the Republican Governors Association — in her home state, saying she was “not doing the job.” And he hit Mitt Romney, the 2012 Republican nominee, calling him a “choker” and mocking his gait, saying he walked “like a penguin.”

Mr. Trump, who lent his campaign money during the primaries, has begun fund-raising for the general election, and there are signs that high-dollar donors are willing to help, especially by donating to a super PAC supporting him. But there are several such groups, and the campaign has yet to unofficially sanction one, leaving some donors confused about which super PAC, if any, they should support.

There are now two super PACs that have said they are the premier group supporting the presumptive nominee, neither of which Mr. Trump has given his blessing. Mr. Trump’s aides have held meetings about starting yet another super PAC, but so far they have not made moves.

Woody Johnson, the Jets football team owner and a Republican fund-raiser, who this week committed to helping Mr. Trump raise hundreds of millions of dollars in a short time period, said he did not believe that the unsettled nature of the presumptive nominee’s campaign would be a hindrance.

“There’s no such thing as job security in a campaign,” Mr. Johnson said of the churn within the Trump team.

But Mr. Reed stressed that Mr. Trump needed to grow — and fast. “Trump is the King Kong of the G.O.P., and when he steps, the world rattles,” he said. “Trump needs to better fully appreciate and understand this new role.”（source: New York Times）