Former Trump campaign manager Corey Lewandowski said Tuesday that whoever is responsible for writing the should be fired.
"Whoever was the staff person who wrote this speech should be held accountable and should be fired," Lewandowski told CNN's John Berman and Kate Bolduan.
Lewandowski, who is a CNN contributor, was fired from the Trump campaign last month.
Republican National Committee Chairman Reince Priebus said at a Bloomberg Politics event Tuesday morning he'd "probably" fire whoever was responsible for including plagiarized quotes, though he added: "It all kinda depends on the circumstances and how these things are written."
The controversy quickly overshadowed the speech, which was to have been her introduction to voters. It focused on her immigration to the United States and her love for her husband.
The Trump campaign released a statement on the speech after the similarities were uncovered, but it did not mention the plagiarism charge.
"In writing her beautiful speech, Melania's team of writers took notes on her life's inspirations, and in some instances included fragments that reflected her own thinking. Melania's immigrant experience and love for America shone through in her speech, which made it such a success," according to Jason Miller, the senior communications adviser.
New Jersey governor and Donald Trump ally Chris Christie defended the speech, saying, "There's no way that Melania Trump was plagiarizing Michelle Obama's speech."
"I just don't see it," Christie told CNN's Jamie Gangel in an interview Tuesday, adding later, "If we're talking about 7% of a speech, that was really, universally considered to be a good performance by Melania. I know her. There's no way that Melania Trump was plagiarizing Michelle Obama's speech."
Who wrote the speech?
Side-by-side comparisons of the transcripts show the text in Trump's address following, nearly to the word, the would-be future first lady's own from the first night of the Democratic convention in Denver nearly eight years ago.
Sources familiar with the campaign's handling of Melania Trump's speech identify top Manafort deputy Rick Gates as the person inside the campaign who oversaw the entire speech process for Melania Trump.
Gates is denying he oversaw the process of putting together the speech.
When CNN's Jim Acosta asked Gates if he oversaw the Melania Trump speech process, he said "absolutely not."
Manafort, on CNN's "New Day," said the scrutiny over Melania Trump's speech was the work of Clinton's campaign.
"This is once again an example of when a woman threatens Hillary Clinton, she seeks out to demean her and take her down. It's not going to work," he said.
However, Trump's aides haven't pointed to any evidence of Democrats' involvement in fanning the controversy.
The Clinton campaign's communications director Jennifer Palmieri said Manafort's comments about Clinton's involvement were untrue.
"Nice try, not true. @PaulManafort, blaming Hillary Clinton isn't the answer for ever Trump campaign problem," Palmieri tweeted
Clinton's campaign on Tuesday focused instead on bashing Republicans for other speeches Monday night, including the mother of a Benghazi attack victim saying she'd like to see Clinton imprisoned and the crowd chanting at another point, "Lock her up!" In a fundraising email to supporters, Clinton's campaign said "there's a difference between drawing a contrast and baselessly saying your opponent belongs in jail."
White House Press Secretary Josh Earnest told reporters Tuesday that President Barack Obama did not watch Monday night's speeches.
"As it relates to Mrs. Trump's speech, I'll let all of you weigh in on all of that and try to learn more about how exactly it was written," Earnest said. "What I can say that in 2008, when Mrs. Obama spoke, she received an enthusiastic reception and strong reviews because of her words, her life story, and the values that she and her husband deeply believe in and try to instill in their kids."