Until Monday night, Donald J. Trumpâ€™s biggest concern about his convention speech was how much to reveal about himself and his family in an address that is often the most personal one a presidential candidate delivers.
But the political firestorm over his wifeâ€™s speech, which borrowed passages from Michelle Obamaâ€™s convention remarks in 2008, raised the stakes exponentially. Mr. Trumpâ€™s speech on Thursday night cannot merely be his best ever.
It also has to be bulletproof.
By Tuesday morning, word had spread throughout his campaign that any language in Mr. Trumpâ€™s address even loosely inspired by speeches, essays, books or Twitter posts had to be either rewritten or attributed.
Mr. Trumpâ€™s chief speechwriter, Stephen Miller, reassured colleagues that the acceptance speech was wholly original, according to two staff members who spoke with him and described those conversations on the condition of anonymity. Mr. Miller also told campaign aides that he had looked closely at passages that Mr. Trump had contributed â€” handwritten on unlined white pages â€” and was confident they contained no problems. (Mr. Miller declined an interview request.)
Even so, one of the staff members downloaded plagiarism-detection software and ran a draft of the speech through the program. No red flags came up.
The intense scrutiny of Mr. Trumpâ€™s words added new pressure to a speechwriting process that has been one of the most unpredictable and free-form in modern presidential campaigns. A month ago, Mr. Trump began giving dictation on themes for the speech, and he tossed ideas and phrases to Mr. Miller or other advisers on a daily basis. On printed copies of each draft, he circled passages he liked, crossed out or put question marks beside lines that he did not favor and frequently suggested new words or phrases.
â€œIâ€™ve been amending the drafts big-league,â€ Mr. Trump said in an interview in his Manhattan office before the convention. â€œI get ideas from a lot of different places, a lot of smart people, but mostly I like language that sounds like me.â€
Yet in the aftermath of Melania Trumpâ€™s speech, campaign advisers have fretted that they do not know for sure where Mr. Trump gets his ideas and language â€” whether they are his own, in other words, or are picked up from Twitter, television, or, say, a best seller by Bill Oâ€™Reilly of Fox News, a commentator whom Mr. Trump likes.
Borrowing or adapting may not always be tantamount to plagiarism, but several Trump advisers, who also insisted on anonymity, said that after the furor over Ms. Trumpâ€™s remarks, the campaign cannot allow a similar blowup.
Ed Rollins, a Republican strategist who is advising a â€œsuper PACâ€ supporting Mr. Trump, said that the candidate could not afford any mistakes.
â€œHis speech is the whole game,â€ Mr. Rollins said. â€œViewers have to watch it and say, â€˜There is the next president of the United States.â€™â€
In the interview, Mr. Trump said his speech would center on his vision of a strong and secure America that â€œonce existed and no longer does, but can again under a Trump administration.â€
His greatest challenge, he said, was â€œputting myself in the speechâ€ â€” discussing his upbringing and early experiences and relating them to the hopes and aspirations of other Americans.
â€œI was never comfortable getting personal about my family because I thought it was special territory,â€ Mr. Trump said, glancing at a picture of his father on his desk. â€œIt can feel exploitative to use family stories to win votes. And I had a very happy and comfortable life growing up. I had a great relationship with my father. But my focus needs to be on all the Americans who are struggling.â€
He said he was unsure if he would discuss his older brother Fred, who died as an alcoholic in 1981 at 43 â€” and whom he has described as an example of how destructive choices can damage lives that seem golden.
â€œWithout my brother Fred I might not be here,â€ Mr. Trump said. â€œHe was really smart, great-looking. I donâ€™t drink or smoke because of what happened to him. I focused on building my business and making good choices. I may talk about that, but I donâ€™t know if I should.â€
Acceptance speeches seldom seem complete without anecdotes about personal trials and triumphs: Mitt Romney, trying to persuade voters to see him as more than a rich businessman, devoted about a fourth of his 2012 address to his parentsâ€™ unconditional love, his Mormon faith and reminiscences about watching the moon landing. In 2008, Barack Obama described how his grandfather benefited from the G.I. Bill and how his mother and grandmother taught him the value of hard work. And Bill Clintonâ€™s 1992 speech vividly recalled the life lessons he learned from his mother about fighting and working hard, from his grandfather about racial equality â€” and from his wife, Hillary, who, Mr. Clinton said, taught him that every child could learn.
Mr. Clinton finished his speech with a now-famous line tying his Arkansas hometown to the American dream. â€œI end tonight where it all began for me,â€ he said. â€œI still believe in a place called Hope.â€
James Carville, a senior strategist for Mr. Clintonâ€™s 1992 campaign, said that if Mr. Trump hoped to change the minds of those who see him as divisive or bigoted, he would need to open himself up to voters in meaningfully personal ways in his speech.
â€œIf heâ€™s really different than the way he seems in television interviews or at his rallies, Thursdayâ€™s speech will be his single greatest opportunity to show voters who he really is,â€ Mr. Carville said.
Paul Manafort, the Trump campaign chairman, said that Thursdayâ€™s speech would be â€œvery much a reflection of Mr. Trumpâ€™s own words, as opposed to remarks that others create and the campaign puts in his mouth.â€
â€œHeâ€™s not an editor â€” he is actually the creator of the speech,â€ Mr. Manafort said. â€œMr. Trump has given Steve Miller and I very specific directions about how he views the speech, what he wants to communicate, and ways to tie together things that he has been talking about in the campaign. The speech will end up being tone-perfect because the speechâ€™s words will be his words.â€
Mr. Trump prefers speaking off the cuff with handwritten notes, a style that has proved successful at his rallies, where he has shown a talent for connecting with and electrifying crowds. But his adjustment to formal speeches remains a work in progress: He does not always sound like himself, and reading from a text can detract from the sense of authenticity that his supporters prize.
One question is whether, or how much, he will ad-lib.
He has sometimes seemed unable to resist deviating from prepared remarks, often to ill effect â€” ranting about a mosquito, or joking that a passing airplane was from Mexico and was â€œgetting ready to attack.â€
â€œAd-libbing is instinct, all instinct,â€ Mr. Trump said. â€œI thought maybe about doing a freewheeling speech for the convention, but that really wouldnâ€™t work. But even with a teleprompter, the speech will be me â€” my ideas, my beliefs, my words.â€