President Donald Trump speaks at a campaign rally at US Bank Arena in Cincinnati. Photo / AP
Despite more than 20 Democratic candidates clamouring to be nominated presidential hopeful for the party, film maker Michael Moore says there is only one person who is guaranteed to "crush" Donald Trump at the next election - and it's none of the them.
The controversial director, who famously tipped Trump to win the 2016 election, has told MSNBC that Michelle Obama is strongest option to topple the president.
The former first lady has said repeatedly she has no interest in running for public office but Moore said someone should ask her.
"Everyone's now saying she's not going to run. Well has anyone asked her?" he told MSNBC. "If asked to serve I believe she would serve."
Moore made his comments as the Democratic presidential candidates wrapped up their second primary debate. Former Vice President Joe Biden leads the polls for the nomination, which will be decided next year.
Moore argued that the former first lady had the popularity to deny Trump a second term in office.
"The only way to remove Trump is to crush Trump. And that's the question that has to be asked, who can crush Trump? Who's the street fighter?," Moore said.
"I think there is one person who can do that," he added, naming Michelle Obama. "I think she would win. She would crush him."
He argued Obama, a former lawyer, would be able to handle Trump on the debate stage and not fall victim to the president's tendency to give his rivals condescending nicknames.
"She would beat him in the debates, he wouldn't be able to bully her, he wouldn't be able to nickname her," he said. "She takes the stage and is so powerful and so good you just look at that and think of course she could win."
Michelle Obama was critical of Trump when she campaigned for Democrats in the 2016 election. But he never gave her a nickname nor hit out at her - unlike his attacks on Hillary Clinton and other Democratic rivals.
"She is beloved. Just go to C-SPAN and follow her book tour across the country," he said.
The former first lady's book sold over 10 million copies and is one of the best selling memoirs of all time.
But she has repeatedly resisted the call to run for public office herself.
"My sense is that, first of all, you have to want the job," she said at the 39th Annual Simmons Leadership Conference in March of last year.
"I've never had the passion for politics," she noted. "I just happened to be married to somebody who has the passion for politics, and he dragged me kicking and screaming into this arena."
Michelle Obama was named the Most Admired Woman in the World in a July YouGov poll, beating out Queen Elizabeth, Angelina Jolie, and Oprah Winfrey.