Is Keith Ellison the man who can stop US President Donald Trump?

He's the frontrunner to become the next Democratic National Committee chairman.

And if he wins his party's top job that could spell very bad news for Donald Trump.

Keith Ellison is the man the Democratic Party hope can turn the party's fortunes around and maximise the anti-Trump sentiment surging in the US, news.com.au reported.

The Democratic National Committee will this weekend hold an election to determine who will be its next chairman.

Just this week, filmmaker Michael Moore declared Ellison to be the man to win the job and could be the one who can overhaul a broken party.

"Progressive Democrat Congressman Keith Ellison appears to be the frontrunner for this Saturday's vote to head the Democratic Party - and to FIX the whole damn mess," Moore wrote in a Facebook post.

The contest comes with Democrats facing a power deficit in Washington and around the country after years of losses in Congress, governor's mansions and statehouses, while also having no unifying national leader since former President Barack Obama left the White House.

Ellison, a former defence lawyer has been a vocal critic of Trump but also correctly predicted he would clinch the presidency last year.

But what do we know about him?

RISING STAR

The 53-year-old, who was born in Detroit Michigan, is a father to four children.

Ellison was not only the first Muslim to be elected to Congress but was also the first African-American to be elected to the US House from Minnesota.

Raised a Catholic, Ellison converted to Islam while a college student.

One of only two Muslims in Congress, Ellison has been a vocal critic of Trump and months ago warned Democrat voters ahead of the election and Trump's win in the primaries that it was time for people to vote and get active - or face the consequences.

"Anybody from the Democratic side of the fence who thinks that - who is terrified of the possibility of President Trump - better vote, better get active, better get involved because this man has got some momentum, and we'd better be ready for the fact that he may be leading the Republican ticket,' he said told ABC show This Week.

While host George Stephanopoulos dismissed the idea, Ellison went on to say if former wrestler Jesse Ventura could win the governorship in Minnesota anything was possible.

But if Trump is worried about the rise of Ellison, he hasn't shown it and just days ago even praised the Minnesota congressman for predicting his victory.

HOPE AND RESISTANCE

According to Dougal Robinson, research fellow at the US Studies Centre at Sydney University, Ellison has an important job ahead - to make the democrats competitive.

"There is an active debate about the direction of the Democratic Party after Hillary Clinton lost an election that was supposed to be unlosable," Robinson told news.com.au.

"Keith Ellison is the leading progressive on the left of the Democratic Party. His supporters argue that Democrats need to energise their base rather than moving to the political centre; that the 'Bernie Sanders' wing of the party represents Democrats' best future.

He said as a Muslim African-American, Ellison "embodies" the Democrats' racial and religious diversity.

"Ellison is appealing because he promises to energise Democrats' 'resistance' to President Trump. He has been supported by Bernie Sanders, Senate Minority leader Chuck Shumer, Senator Elizabeth Warren, recently retired Democratic Senate leader Harry Reid, civil rights icon John Lewis and prominent feminist Gloria Steinem."

He said most Republicans would have no problem with Ellison taking the top position.

"Many would be pleased to see Ellison elected as DNC chair, because they see him as a left-wing progressive who will struggle to rebuild the party's fortunes with working class white voters who propelled Donald Trump to victory in the 2016 presidential election."

OVERHAUL THE PARTY

This weekend, 447 members of the Democratic National Committee will be casting their votes in Atlanta.

Along with Ellison, Labor Secretary Tom Perez and mayor of South Bend, Indiana Pete Buttigie are the other contenders.

Ellison, backed by Vermont Senator Bernie Sanders and his supporters, has the support of about 153 members.

The Democrats are looking for a way forward and are hoping to harness the energy of an opposition movement that has flourished since Trump took office.

They hope Ellison can be the man to re-engage disillusioned voters and political groups loyal to the Democrats and add new vigour into the party.

Party hopefuls are relying on a fresh face to drive voters to the polls in gubernatorial and special House elections this year and congressional mid-terms next year.

Republicans control the White House, Congress, 33 governorships and, if Trump's Supreme Court nominee Neil Gorsuch is confirmed, a conservative advantage on the high court.

Tapping the passion of the resisters could lift the party and increase the Democrats' power.

"The grassroots cannot win without political powers, and the political powers cannot win without the grassroots," said Brad Bauman, a liberal Democratic consultant who previously ran the Congressional Progressive Caucus.

"There's a natural distrust there, but they have to figure out how to make it work."

Even the leading candidates for the next national Democratic Party chairman agree.

"The energy is electric," said former Labor Secretary Tom Perez, who is battling Ellison and others for the party's top post.

The chair candidates, other potential DNC leaders, state party executives and the leaders of the liberal groups are talking about how to maximise the anti-Trump surge that began with street demonstrations last month and has continued this week as Republican members of Congress meet angry constituents at town halls across the country.

TRUMP SLAMMED

This week, Ellison said Trump has done enough to justify him getting booted out of office.

"I think that Donald Trump has already done a number of things which legitimately raise the question of impeachment," he told CNN on Wednesday.

"On day one, he was in violation of the emoluments clause. This is a part of the Constitution that says as president, you can't get payments from a foreign power," Ellison continued after the CNN audience, assembled for a debate between prospective DNC chairs, broke into applause.

"The day people checked into his hotel and started paying him, who were foreign dignitaries, he was in violation of that law. There's already a lawsuit filed against him. And right now, it's about only Donald Trump. It is about the integrity of the presidency," said Ellison.

'TAKE OVER THE DEMOCRATS'

In a Facebook post written this week called Do These 10 Things, and Trump Will Be Toast, Moore writes how the Democrats are in complete disarray.

He wrote he found it hard to believe the Democrats have won the popular vote in six of the seven last elections yet held no power in any branch of government.

"PLEASE, the old leadership has to go. God love 'em for their contributions in the past, but if we don't enact a radical overhaul right now, we are doomed as far as having a true opposition party during the Trump era," he wrote.