After struggling for more than 24 hours to come up with a coherent explanation for how portions of a 2008 speech by Michelle Obama had reappeared in the remarks delivered by Melania Trump at the Republican National Convention, a Trump staff writer said Tuesday that she was responsible and apologised for the "confusion."

In a statement, Meredith McIver said she was an "in-house staff writer." She took responsibility for including the passages from Michelle Obama's speech - though she said she had not revisited the speech herself, only listened as Melania read parts of Obama's speech that she liked to McIver over the phone.

McIver said she offered her resignation to Trump and his family on Wednesday, but they had declined to accept it. "Mr. Trump told me that people make innocent mistakes and that we learn and grow from these experiences," she said.

"I apologise for the confusion and hysteria my mistake has caused," McIver said.


Donald Trump himself addressed the controversy on Twitter.

"Good news is Melania's speech got more publicity than any in the history of politics especially if you believe that all press is good press!" he wrote in one message. And he attempted to shift blame onto his rival, presumptive Democratic nominee Hillary Clinton.

The campaign's attempt to beat back the all-consuming controversy came as the Republican National Convention entered its third day, with scheduled prime-time addresses by former primary rivals of Trump - now officially the party's presidential nominee - and perhaps a new chance to heal the deep rift in the GOP on display here so far this week.

Indiana Governor Mike Pence, Trump's running mate, is expected to speak, reassuring GOP stalwarts that the unpredictable, off-the-cuff businessman is not the exclusive face of a party that some no longer fully recognise.

Paul Manafort, Trump's campaign chairman, continued to deny that the speech showed signs of wrongdoing, telling CNN that the two women employed "similar words," but, because Melania Trump is not a candidate for office, "the controversy that you're talking about is not meaningful at all."

"She was expressing her personal feelings," Manafort said. "That's the final word."

Manafort aimed to redirect attention to Trump's formal nomination - and to the heft Pence will add to the ticket when he speaks this evening - but Republicans gathered here for their national convention celebrated that triumphant milestone not by promoting Trump's personal virtues or policy ideas so much as by leading a three-hour prosecution of Democrat Hillary Clinton.

There were allegations that she had enabled sexual abuse at the hands of her husband. She was accused of having sympathy for Lucifer. There were so many references to her private email server and the 2012 Benghazi attacks that it was hard to keep count.


New Jersey Governor Chris Christie led a call-and-response prosecution of her actions as secretary of state, turning the audience into an ad hoc jury: "Guilty or not guilty?"

The crowd interrupted him four times: "Lock her up!" the delegates chanted. "Lock her up!"

Manafort, at a press conference, said many Americans agree with Republican delegates who took part in the chant. He wouldn't say specifically whether Trump agrees with the sentiment.

"Did it reflect the attitude of people saying it? Probably reflects the attitude of a lot of people in America where over 60, 70 per cent think she's guilty and don't understand why justice wasn't done," Manafort said.

The case for Trump is increasingly being framed as little more than an opportunity to fend off Clinton, the presumed Democratic nominee. Christie, who was perhaps Wednesday's most electric speaker, appeared on MSNBC's "Morning Joe" and made clear that Trump's imperfections don't matter when the alternative is Clinton.

"This isn't a political science class," he said. "This is the real world. There's a binary choice here. It's Donald Trump or Hillary Clinton."

Christie, a former U.S. attorney in New Jersey, also took a swing at James Comey, the director of the FBI, for concluding that there wasn't sufficient evidence to recommend charges against Clinton in the investigation into her use of a private email server. He said Comey should have simply laid out the evidence and let the attorney general decide. "He forgot his job," Christie said.

Thursday's program will unfold under the banner, "Make America First Again." It will feature former several primary rivals, including Texas Senator Ted Cruz and Wisconsin Governor Scott Walker, as well as Newt Gingrich, a former speaker of the House who was in the running to be Trump's running mate, and Trump's son, Eric.

On Wednesday, when remarks were billed under the theme "Make America Work Again," convention viewers were served a buffet of scattered messages and discordant ideas, underscoring the party's divisions and discomfort with Trump. For instance, overhauling trade deals has been a cornerstone of Trump's economic agenda, yet there was relatively little mention of his ideas about trade.

Nor were there many mentions of his other signature ideas: building a wall on the southern U.S. border, barring foreign-born Muslims from entering the country and deporting undocumented immigrants en masse.

House Speaker Paul D. Ryan (Wisconsin) gave the most substantive and muscular speech about conservatism. But the man who four years ago got a rock-star reception at the GOP convention as Mitt Romney's vice-presidential running mate was coolly received by Trump delegates in the convention hall.

Ryan, who has uneasily endorsed Trump, spoke mostly about his agenda for House Republicans. Addressing the turmoil Trump has wrought on the party, Ryan said, "Democracy is a series of choices. We Republicans have made our choice."

The most effective character testimonials came from two members of the Trump family - Donald Jr. and Tiffany - who tried to convince people their father is more compassionate and trustworthy than the caricature of Trump.

"Donald Trump has never done anything halfway, least of all as a parent," said Tiffany, 22, his daughter from his second marriage with Marla Maples, who was in attendance.

Tiffany added, "My dad is a natural-born encourager, the last person who will ever tell you to lower your sights."

Donald Jr., 38, delivered a particularly forceful defense of his father and tried to explain his appeal to blue-collar America. He described how his father mentored him at construction job sites and he condemned a system that benefit "our new aristocrats."

"He didn't hide out behind a desk in an executive suite. He spent his career with regular Americans. He hung out with the guys at construction sites... pouring concrete and hanging sheetrock."

At 7:12 p.m., Donald, Jr., stood on the convention floor - locking arms with siblings Ivanka, Eric and Tiffany - and ceremonially cast New York state's 87 Trump delegates for his father, pushing him over the required 1,237-delegate threshold.

"It is my honor to be able to throw Donald Trump over the top in the delegate count tonight," Donald Jr. said. "Congratulations, Dad, we love you!"

With chants of "Trump! Trump! Trump!" filling Quicken Loans Arena in downtown Cleveland and a band playing an instrumental version of "New York, New York," the Trump children fought back tears, visibly moved by the emotion of the moment.

The political drama faded some Wednesday, after Trump's allies squelched the efforts of some rebellious delegates to disrupt the convention, an undertaking that followed their failed attempts to derail procedures binding Trump's delegates to him.

There were spurts of dissent, some unspoken. For instance, when it came time for New Mexico Gov. Susana Martinez, R. to announce her state's support for Trump, she turned the microphone over to a fellow delegate to utter Trump's name. Trump has publicly chastised Martinez for her refusal, so far at least, to endorse him.

But the final roll call was decisive: 1,725 delegates for Trump, followed by 425 for Sen. Ted Cruz (Texas), 120 for Ohio Governor John Kasich, 114 for Senator Marco Rubio (Florida), seven for retired neurosurgeon Ben Carson, three for former Florida governor Jeb Bush and two for Senator Rand Paul (Kentucky).

Some of Trump's most loyal backers briefly sang his praises during the roll-call proceedings. Senator Jeff Sessions (Alabama) declared him "a warrior and a winner." Rep. Chris Collins (New York) said he was "not merely a candidate. Donald Trump is a movement." And South Carolina Lt. Governor Henry McMaster veered in his remarks from unbridled happiness about Trump to deep pessimism about the state of the country he wants to lead.

"Weakness, decline, and ultimately, chaos and oblivion. We feel an eerie unease," McMaster said, describing the state of the nation under President Barack Obama. "But, ladies and gentlemen, that is about to change."