WASHINGTON • Turmoil in the Republican Party has escalated as party leaders, strategists and donors voiced alarm about the flailing state of the candidacy of real estate mogul Donald Trump, and fears that the presidential nominee was damaging the party with an extraordinary week of self-inflicted mistakes, gratuitous attacks and missed opportunities.

Republican National Committee chairman Reince Priebus was described as "very frustrated" with and deeply disturbed by Mr Trump's behaviour over the past week, having run out of excuses to make on the nominee's behalf to donors and other party leaders, according to multiple people familiar with the events.

Meanwhile, Mr Trump's top campaign advisers are struggling once again to instil discipline in their candidate, who has spent recent days lunging from one controversy to another while seemingly skipping chances to go on the offensive against Democratic opponent Hillary Clinton. "A new level of panic hit the street," said Mr Scott Reed, chief strategist for the United States Chamber of Commerce. "It's time for a serious reset."

Trump allies on Wednesday publicly urged the candidate to reboot, furious that he has allowed his confrontation with the Muslim parents of dead army captain Humayun Khan to continue for nearly a week. They also are angry with Mr Trump because of his refusal to endorse two top GOP elected officials - House Speaker Paul Ryan and Senator John McCain - ahead of their upcoming primary elections.

Campaigning in Florida, Mr Trump sought to pivot away from his problems. He addressed the controversy and speculation, saying his campaign is "doing really well" and has "never been this well united", then focused renewed attacks on Mrs Clinton and President Barack Obama.

But the idea that the campaign was fully united was undercut when his vice-presidential running mate Mike Pence told Fox News that he "strongly endorsed" Mr Ryan in his primary campaign. Other Republicans viewed the endorsement as a sign that he is having some influence within the campaign, said a person familiar with Mr Pence's role.

Mr Trump also suffered two defections on Wednesday when Representive Adam Kinzinger, an Iraq war veteran, said on CNN that he is unlikely to vote for Mr Trump because the nominee was "beginning to cross a lot of red lines of the unforgivable in politics". Former Montana governor Marc Racicot also said he would not vote for Mr Trump. "There's a transcendent set of values throughout our history that we subscribe to above party," Mr Racicot told Bloomberg Politics, adding that he thinks Mr Trump lacks those values.

Campaign manager Paul Manafort went on cable channels to try to tamp down the rampant Trump criticism, saying that reports of a campaign staff in crisis were incorrect. He said the campaign is "focused", in "very good shape" and "moving forward".

There were also persistent reports that allies of Mr Trump were trying to arrange a meeting with him to urge him to refocus his candidacy. Mr Manafort, when asked on Fox News about such a meeting, said he knew nothing about it. A knowledgeable GOP strategist said: "It doesn't take a genius to know that calling Donald Trump and yelling at him is never going to work."

WASHINGTON POST