Supreme Court justice Ruth Bader Ginsburg's death has roiled the US presidential race, with the battle over her replacement looming large in swing states likely to determine the course of an election just six weeks from Tuesday.

Many Republicans see her passing as a golden if controversial opportunity for President Donald Trump to pick another conservative -- his third -- for a lifelong spot on the nine-member bench.

Michelle Burns, a stay-at-home mother of six in the small city of Monroe, in southern Michigan, said "it's God's will" that Trump fill the court vacancy before the vote.

US President Donald Trump said he will soon nominate a replacement for the late Supreme Court justice Ruth Bader Ginsburg
US President Donald Trump said he will soon nominate a replacement for the late Supreme Court justice Ruth Bader Ginsburg AFP / MANDEL NGAN

"My own belief is that this was a divine intervention," the 46-year-old told AFP Monday outside her home that features over-the-top Halloween decorations complete with an inflatable Trump.

"What's the coincidence of it happening seven weeks before the election?"

Trump's battle with Democrat Joe Biden is on a razor's edge, with the Ginsburg replacement the latest in a series of bitterly divisive election issues: Trump's handling of the coronavirus pandemic, the resulting economic downturn, and tensions over racial injustice.

Many backers of US President Donald Trump expressed support for his plan to nominate a new justice to fill a vacancy on the Supreme Court ahead of the November 3 presidential election
Many backers of US President Donald Trump expressed support for his plan to nominate a new justice to fill a vacancy on the Supreme Court ahead of the November 3 presidential election AFP / MANDEL NGAN

Whether the explosive Ginsburg issue fundamentally alters the race is not yet known.

But grassroots Democrats hope Trump nominating a replacement would be met with a backlash that tilts the presidential contest their way in critical Industrial Belt states like Michigan and Ohio.

"It's really life or death at this point," said 21-year-old college student Alexa Cooley, as she and her sister left a Democratic Party office in Monroe with campaign yard signs under their arms.

Republican Michelle Burns, posing in front of her home in Monroe, Michigan, says 'it's God's will' that President Donald Trump fill the Supreme Court vacancy before the election
Republican Michelle Burns, posing in front of her home in Monroe, Michigan, says 'it's God's will' that President Donald Trump fill the Supreme Court vacancy before the election AFP / Bastien INZAURRALDE

While she acknowledges the court seat battle is a rallying point for pro-life voters like Burns, Cooley sees a five-alarm fire that will "motivate Democrats" to vote for Biden on November 3.

"Especially with Ruth Bader Ginsburg, we could go to Gilead," Cooley said, refering to the patriarchal theocracy in the dystopian novel "The Handmaid's Tale."

"A lot of my friends are talking about, 'our lives are going to be the Handmaid's Tale, all our rights are going to be taken away'" if a conservative majority court strikes down landmark cases protecting women's rights, she said.

A Trump yard sign and Halloween decorations outside the house of Trump supporter Michelle Burns in Monroe, Michigan
A Trump yard sign and Halloween decorations outside the house of Trump supporter Michelle Burns in Monroe, Michigan AFP / Bastien INZAURRALDE

"That's what women my age are concerned about."

Monroe County was one of several in Michigan that voted twice for Barack Obama but flipped to Trump, helping him narrowly carry the state and propel him to a 2016 shock win.

Monroe resident James Pocock believes Biden will have to fight hard to win back the county, and said the Supreme Court battle will only intensify the drama.

"I feel like it's going to cause a lot of conflict," the 21-year-old said.

Student Alexa Cooley (posing outside her home in Monroe, Michigan) says the court seat battle will 'motivate Democrats' to vote for Joe Biden
Student Alexa Cooley (posing outside her home in Monroe, Michigan) says the court seat battle will 'motivate Democrats' to vote for Joe Biden AFP / Bastien INZAURRALDE

Pocock is Republican and comes from a pro-life family, so there is pressure to fall in line and back the president.

But he believes Trump has done "questionable things in office" and has badly mishandled the coronavirus, and so Pocock's vote, he said, is going to Biden, despite Pocock's own opposition to abortion.

Trump has announced he will nominate a new justice soon and the Senate's Republican leader said to expect a confirmation vote.

The move so close to an election has infuriated Democrats. But in neighboring northwestern Ohio, a closely watched bellwether state won by Trump in 2016, supporters streamed into Trump's Monday open-air rally eager for the president to fulfill his duty.

"It's really important for President Trump to push through another nominee for the Supreme Court (who) believes in life, who believes in the constitution, believes in liberty," said realtor Holly Orman of Toledo as she entered the rally in nearby Swanton.

Orman, 44 and wearing a T-shirt that read "Jesus is my savior, Trump is my president," said the economy was paramount in 2020 but that the court vacancy was vital too, and that Democrats "should back off and let (Trump) do his job."

Most rally attendees appeared unconcerned about the Supreme Court showdown having a damaging effect on Trump's re-election effort.

"He's rushing it, and I think he should," Paula Nowicki, wearing a pink "Women for Trump" hat, said of the president's planned nomination.

Her 30-year-old daughter Becky Nowicki, an insurance producer, is a fervent Trump supporter but broke with her mother when asked if she felt the issue could turn the election against him.

"Honestly I feel like we could see anything in 2020 so I think it could -- which is terrifying," she said.

Trump appeared to relish the opportunity to discuss the vacancy with his pumped-up fans.

"We're going to put up our nominee who's going to be outstanding," he said to loud cheers.

"They say it's the most important thing a president can do," Trump added, as his faithful chanted in agreement: "Fill that seat! Fill that seat!"