WASHINGTON (BLOOMBERG) - US President Donald Trump's nomination of Mrs Amy Coney Barrett is poised to give the Supreme Court its most conservative female justice in history but is unlikely to accomplish the one thing that could help seal his re-election - a new surge of support from women, a segment of the electorate his campaign has struggled to attract.

Mr Trump on Saturday named Mrs Barrett to replace the liberal jurist and feminist icon Ruth Bader Ginsburg, fulfilling his pledge to nominate a woman.

The difference between the two women's views couldn't be more stark: Mrs Ginsburg was a champion of preserving a woman's right to an abortion, while Mrs Barrett says abortion is "always immoral" and has already ruled as a circuit court judge to restrict the procedure.

If the Senate confirms Mrs Barrett, which is likely, given its Republican majority, the pick keeps the court's gender balance at six men and three women. Mrs Barrett would be the only woman on the court's conservative wing.

The move poses a risk for Mr Trump. Since Mrs Sandra Day O'Connor became the first woman on the court almost 40 years ago, the reaction to Mrs Barrett's appointment and polling data suggests women are looking at a nominee's potential rulings and judicial record as much or more than her gender.

Conservative women who oppose abortion rights are already in Mr Trump's camp, but they are a small minority of women voters. Surveys show that very few women, if any, are going to switch their support from Democratic nominee Joe Biden based on Mr Trump's choice of a female jurist. Instead, there are signs that it could actually drive Democrats to polls.

Republican activists say their voters are eager to hear Mrs Barrett's voice from the bench. Her appointment "energises the very same voters, the women voters, that are faithful Catholics and evangelical and encourages them to once again return Donald Trump to the White House", said Ms Penny Nance, president of Concerned Women for America.

But with the election just more than a month away, Mr Trump's campaign was hoping a female nominee could attract some new women voters, especially in the suburbs.

"For Donald Trump to win, he needs to close that gap with women," said Ms Sarah Longwell, a Republican strategist who founded Republican Voters Against Trump. The White House seems to think nominating a woman will help them with women voters, she said.

"What they don't realise is that it may actually backfire on them because a lot of these suburban women that they need actually won't like the idea of somebody who is very far right ideologically taking Ruth Bader Ginsburg's seat on the Supreme Court."

Most women don't support Mr Trump. A national poll by Quinnipiac University released Wednesday showed that 58 per cent of women backed Mr Biden, while 38 per cent backed Mr Trump - a 20-point gap that amounted for the entirety of Mr Biden's overall lead. Among men, Mr Trump and Mr Biden were essentially tied at 47 per cent to 46 per cent.

Even in Republican states whose voters largely support Mr Trump, it's women who cut into his lead. Mr Biden leads Mr Trump among women by 10 percentage points in Georgia, 14 points in Iowa and 8 points in Texas, all states where Trump leads overall, according to a New York Times/Siena College poll released last week.

Mrs Ginsburg's death just sharpens that divide, given that most women say they don't believe Mr Trump should fill her seat at all.

A CNN poll found 65 per cent of women believe the winner of the November election should fill the seat, compared with just 52 per cent of men. Women were also more likely to say that Mr Trump's appointments have "changed the court for the worse".

Democrats and progressive groups have seen a surge of donations since Mrs Ginsburg's death and will portray the nomination as a threat to abortion rights, the Affordable Care Act and LGBTQ rights.

The Supreme Court vacancy is more motivating for Democrats, said Ms Nancy Zdunkewicz, a Democratic pollster with Change Research.

"The conventional wisdom that the politics of Supreme Court vacancies are more motivating for conservatives - this is not what we see in the data," she said. "It's not in the data, not even kind of. It's looking more important for suburban white college-educated women who are liberal."

Polls have shown that 70 per cent of women oppose overturning the Roe v. Wade ruling on abortion rights, a number that has steadily risen over the years.

Mr Biden is capitalising on those numbers, warning that allowing Mr Trump to pick Mrs Ginsburg's replacement threatens not only the Affordable Care Act, but "women's health", widely seen to mean abortion rights.

"I think Amy Coney Barrett, her record is going to be a big driver of Democratic engagement in this election - and so is the interest in protecting Ruth Bader Ginsburg's legacy," said Ms Shaunna Thomas, cofounder of UltraViolet, a feminist advocacy group.

Mrs Ginsburg became the nation's second female Supreme Court justice when President Bill Clinton appointed her in 1993. She was the court's only woman from 2006, when Mrs O'Connor retired, to 2009, when Justice Sonia Sotomayor joined the court. Justice Elena Kagan was confirmed a year later.

Mrs Barrett's confirmation would guarantee that the court will have at least three female justices for the foreseeable future. The court could get a fourth if Mr Biden wins and keeps his promise to nominate a Black woman if he gets the opportunity.

Until now the biggest sceptics of reproductive rights on the court have all been men. In 2014, when the court ruled 5-4 that companies can refuse on religious grounds to offer their workers the free birth control promised under the Affordable Care Act, five men were in the majority and all three female justices dissented.

Now Mrs Barrett is likely to join the conservative bloc on the court, comprised of Chief Justice John Roberts and Justices Clarence Thomas, Samuel Alito, Neil Gorsuch and Brett Kavanaugh, all Republican appointees. She will be a new face for originalism, which focuses on the original meaning of the Constitution's words and casts doubt on Roe v. Wade.

"I'm excited about having a constitutionalist, originalist woman on the court," said Ms Carrie Severino, president of the Judicial Crisis Network, which backs Mr Trump's judicial nominees. "This will be our first originalist woman, and it illustrates the breadth and diversity of opinions among women in the law, and I think that's a great thing for Americans to see."

Mrs Barrett, a Catholic mother of seven, wrote in a 1998 law review article that abortion and euthanasia "take away innocent life" and that abortion is "always immoral". She could be just as valuable a role model to young women as Mrs Ginsburg was and that serves a broader purpose than Trump's re-election, Ms Nance said.

"There was a lot being said about Ruth Bader Ginsburg being a role model for women and I would agree with that - but I would say there's never been a conservative woman justice. So we are very eager for there to be a role model for our daughters," she said.