WASHINGTON — Paula Duncan didn't wear her red "Make America Great Again" hat when she arrived in court to serve on Paul Manafort's jury.

She kept it in her car, she tells NBC News.

But Duncan, an ardent supporter of President Donald Trump, came to the Manafort trial thinking that Robert Mueller's Russia investigation is a witch hunt that is maligning a good president and dividing America.

She still thinks so.

But she also had no doubt that Paul Manafort, once Trump's campaign chairman, was guilty. She would have convicted him on all counts, she said, but she and 10 other jurors were stymied by a lone holdout.

And no, she doesn't believe that person, a woman, was a Trump supporter.

"I wanted Paul Manafort to be innocent, but he wasn't," Duncan told NBC News.

Duncan, a homemaker who lives in Leesburg, Virginia, said she believes Manafort was a "pawn," in Mueller's Russia probe, an investigation about which she has serious doubts.

She's not even sure Russia interfered in the election.

"I as a voter, when I went out to check my boxes I didn't see any Russian holding a gun to my head, so how could Russia have affected the campaign results," said Duncan, who first spoke to Fox News.

However, she said, the government presented compelling evidence that Manafort, who was Trump's campaign chairman, evaded taxes and defrauded banks.

"In the end I did what we needed to be done," she said. "I did the right thing."

During jury selection, she kept her political leanings to herself, she said.

"I didn't believe politics had any place in that courtroom, so I was somewhat vague in my answers. I knew I could be fair and impartial."

Most of the other jurors in Alexandria, Virginia, "were probably not of my political leanings," she said.

That includes the lone holdout, about whom Duncan did not want to say much. Duncan was fairly certain, though, that the two didn't see politics the same way.

Most of the jurors agreed by the second day that Manafort was guilty on all counts she said, but there were two skeptics. One came around. But the female holdout refused, despite days of argument by the other jurors.

The jury ended up convicting Manafort of eight counts and deadlocking on 10, which were declared to be in mistrial. The government can retry Manafort on those charges, but given that he faces 10 years in prison, there may not be a reason to do so.

"It was so frustrating," Duncan said. "She just couldn't explain to us why she had reasonable doubt. We could provide her with the information but she wouldn't change her votes."

Judge Ellis addresses the jury of the Paul Manafort trial on Aug. 15, 2018. Art Lien

Duncan said the woman could not explain, for example, why she voted to convict on one count of failing to report a foreign bank account, but not on the other three, which were very similar.

"I think it was about her right to do that," Duncan said. "In the end it may have been more about her determination" to buck the others.

Duncan said none of the jurors put much stock in Rick Gates, who flipped and testified against Manafort. But there was so much other evidence that Manafort's guilt was obvious, she added.

Duncan said she did not hold it against Trump that he allowed a man who was committing crimes to help run his campaign.

"He was running Donald Trump's campaign in my opinion because he was brilliant as a political strategist," Duncan said, noting that even the government's witnesses said as much.

Trump could not have been expected to vet Manafort's finances, she added.

The former juror said she had great affection for the judge in the case, T.S. Ellis. He came under criticism for appearing to favor the defense, but she didn't see it that way.

"I think a lot of his interruptions were what parents would call 'teachable moments,'" she said.

Duncan says she supports Trump's call for Mueller to wrap up his investigation.

"America chose," she said. "The other half of America that lost doesn't want to accept those of us who won. I didn't vote for Obama but I had to accept him as my president. We're getting derailed by this whole special counsel thing — let the man do his job. "

Trump, she said, "is doing a great job."

The jurors' names remain sealed because the judge worried for their safety.