Donald Trump’s pick for America’s highest court, Amy Coney Barrett, is an “ideological fanatic” who threatens abortion rights, healthcare and the environment, activists warned on Saturday, before Trump unveiled his third supreme court nominee in the White House Rose Garden. Barrett is the ideological opposite of the woman she will succeed if confirmed, Ruth Bader Ginsburg, who died earlier this month aged 87. On Saturday, the Rose Garden at the White House was decorated to mimic its layout when Ginsburg was nominated by Bill Clinton in 1993. Trump called Ginsburg a “a legal giant and a pioneer for women” and said “her extraordinary life and legacy will inspire Americans for generations to come”. He added: “Today it is my honor to nominate one of our nation’s most brilliant and gifted legal minds to the supreme court. She is a woman of unparalleled achievement, towering intellect, sterling credentials and unyielding loyalty to the constitution. Judge Amy Coney Barrett.” Barrett, 48, a devout Catholic who serves on the 7th US circuit court of appeals in Chicago, is a favorite of religious conservatives and could seal Trump’s legacy by tilting the court right for a generation. The Republican-controlled Senate will race to confirm his nominee before the presidential election on 3 November. Trump said it “should be a straightforward and prompt confirmation and it should be very easy. Good luck. It’s going to be very quick. I’m sure it’ll be extremely non-controversial. We said that the last time.” That was a reference to a furious political fight over Trump’s second nomination, of Brett Kavanaugh, in 2018. Though Democrats lack the means to stop Barrett, they remain fiercely opposed to her confirmation so close to an election before which Trump trails his challenger, Joe Biden, in the polls. Four years ago, Republicans in the Senate denied Merrick Garland, chosen by Barack Obama to replace Justice Antonin Scalia when he died in an election year, even so much as a hearing. As her husband and seven children looked on, Barrett paid tribute to Ginsburg and to Scalia, for whom she clerked. “Justice Ginsburg began her career at a time when women were not welcome in the legal profession,” Barrett said. “But she not only broke glass ceilings, she smashed them. For that she has won the admiration of women across the country, and, indeed, all over the world.” In front of Republican senators and the US attorney general, Bill Barr, whose roles supporting Trump have attracted immense criticism, Barrett said Ginsburg’s “life of public service serves as an example to us all”. She also seemed to seek to extend a hand across the aisle, remarking that Ginsburg’s friendship with Scalia, an arch-conservative, was “particularly poignant to me”. “Justices Scalia and Ginsburg disagreed fiercely in print, without rancor in person. Their ability to maintain a warm and rich friendship, despite their differences, even inspired an opera. These two great Americans demonstrated that arguments, even about matters of great consequence, need not destroy affection. And in both my personal and professional relationships, I strive to meet that standard.” Few Democrats are likely to respond in kind. As Barrett spoke, Biden released a statement reaffirming his position that Barrett poses a threat to healthcare coverage and that no one should replace Ginsburg until after inauguration day, 20 January. “The United States constitution was designed to give the voters one chance to have their voice heard on who serves on the court,” Biden said. “That moment is now and their voice should be heard. The Senate should not act on this vacancy until after the American people select their next president and the next Congress.” The supreme court is a vital check on presidential power and wields huge influence on American society. A 6-3 rightwing majority would potentially curb abortion rights, strike down gun control laws and uphold new restrictions on voting rights. Meagan Hatcher-Mays, director of democracy policy at the grassroots organisation Indivisible, said: “Justice Ginsburg was a brilliant lawyer who dedicated her life to advancing gender equality and civil rights for everyone. Amy Coney Barrett cannot claim the same. The idea that Amy Coney Barrett could replace RBG on the supreme court is an insult to RBG’s life and legacy.” Other campaigners warned of the threat to the planet posed by Barrett’s likely opposition to environmental regulation. Brett Hartl, government affairs director at the Center for Biological Diversity, said: “Judge Barrett is an ideological fanatic who lacks the temperament to rule fairly in the interests of all Americans. “Her slim judicial record shows that she’s hostile to the environment and will slam shut the courthouse doors to public interest advocates, to the delight of corporate polluters. Environmental justice, our climate and wildlife on the brink of extinction will all suffer if Barrett is confirmed.” Reproductive rights advocacy groups have expressed alarm that Barrett could help overturn the landmark 1973 Roe v Wade decision that legalised abortion. And on 10 November, the court is scheduled to hear arguments in a major case in which Trump and Republicans are seeking to invalidate the 2010 Affordable Care Act, known as Obamacare. If confirmed, Barrett could cast a decisive vote. Brian Fallon, director of the pressure group Demand Justice, said: “Barrett’s views may make her a darling of Trump’s base, but they will also make clear to everyone else that nothing less than the survival of the Affordable Care Act and Roe v Wade are on the line in this fight. Senate Democrats need to be prepared to resist this pick at all costs.” But Democrats have few options. Republicans hold a 53-47 majority in the chamber and only two GOP senators have expressed opposition to moving forward before the election. A vote on the Senate floor is expected by late October. Barrett would be Trump’s third lifetime appointment to the supreme court, a record which, combined with 200 other federal court judges, is seen as crucial in shoring up support among Christian evangelicals and other conservatives. Evangelical leaders met Trump in the Oval Office before the unveiling of Barrett. But Trump’s move could also energise liberal voters to turn out in November. As an appellate judge, Barrett voted in favour of one of Trump’s hardline immigration policies and showed support for expansive gun rights. She also authored a ruling making it easier for college students accused of campus sexual assaults to sue their institutions. Catherine Glenn Foster, president and chief executive of the anti-abortion group Americans United For Life, praised Trump for making a “brave and ambitious choice” and called Barrett “the best and most qualified successor” to Ginsburg. Trump is the first sitting president to attend the annual anti-abortion March for Life in Washington. Jeanne Mancini, president of March for Life, said Barrett’s expected nomination “is welcome and exciting news for everyone who values the rule of law and our constitutional rights”. She added: “We have confidence that she will fairly apply the law and constitution as written, which includes protecting the most vulnerable in our nation: our unborn children. She is a highly gifted jurist and a woman of great accomplishment – a role model for women and girls across the country – and she deserves a vote as expeditiously as possible.” Barrett may even have a role to play in the presidential election. Trump suggested this week that the supreme court would be called upon to rule on the outcome, as it did in favour of George W Bush against Al Gore in 2000. “I think it’s very important that we have nine justices,” the president said. Trump has repeatedly and without evidence said that voting by mail could lead to a surge in election fraud. He also declined to commit to a peaceful transfer of power. Ginsburg made history on Friday as the first woman and first Jewish person to lie in state in the US Capitol. Biden attended, a day after Trump met with jeers and boos as he visited Ginsburg’s casket outside the supreme court building. Ginsburg will be buried next week at Arlington National Cemetery, beside her husband.