Joe Biden, the Democratic presidential nominee, made an urgent plea on Sunday to the conscience of Senate Republicans, asking them to defy Donald Trump and refuse to ram through his nominee to the supreme court before the November election. Trump has said he plans to nominate a woman in the coming days, to fill the seat of Ruth Bader Ginsburg, the liberal justice who died on Friday at age 87. Speaking in Philadelphia, Biden demanded that the people be heard. He accused Mitch McConnell, the Senate majority leader, of hypocrisy after he stonewalled Merrick Garland, Barack Obama’s pick for the court in 2016, also an election year. “Look, I’m not being naive,” the former vice-president said. “I’m not speaking to President Trump, who’ll do whatever he wants. I’m not speaking to Mitch McConnell, who’ll do what he wants, and he does. “I’m speaking to those Republicans out there, Senate Republicans, who know deep down what is right for the country and consistent with the constitution.” People have already begun voting in an election that is just six weeks away, Biden added. “The people of this nation are choosing their future right now, as they vote. To jam this nomination through the Senate is just an exercise in raw political power and I don’t believe the people of this nation will stand for it.” It would represent an “abuse of power”, he said. “This is constitutional abuse.” Biden said he spoke to Ginsburg’s family on Saturday night and noted that the justice dictated a statement to her granddaughter Clara Spera: “My most fervent wish is that I will not be replaced until a new president is installed.” Biden said: “As a nation, we should heed her final call.” The right to healthcare, clean air, clean water, equal pay for equal work and the rights of voters are all at stake, Biden insisted. “Healthcare in this country hangs in the balance before the court.” Biden, who often reached across the aisle in a decades-long career as a US senator from Delaware, added: “We need to de-escalate, not escalate, so I appeal to those few Senate Republicans, the handful who really will decide what happens: please follow your conscience. Don’t vote to confirm anyone nominated under the circumstances President Trump and Senator McConnell have created. “Don’t go there. Uphold your constitutional duty, your conscience, let the people speak, cool the flames that have been engulfing our country. We can’t keep rewriting history, scrambling norms, ignoring our cherished system of checks and balances.” On Saturday night, Trump told a rally in Fayetteville, North Carolina, he would select a female justice. “I actually like women much more than I like men, I have to say,” said a man who has denied accusations of sexual misconduct from more than 20 women, eliciting laughter from a crowd that chanted: “Fill that seat!” On Sunday, Trump’s campaign sent out a fundraising email that said “the People want to FILL THAT SEAT!” Whether enough Republican senators will consent to ram through Trump’s nomination remains on a knife edge. On Sunday, Lisa Murkowski of Alaska joined fellow moderate Susan Collins of Maine in arguing that the Senate should wait. “For weeks, I have stated that I would not support taking up a potential supreme court vacancy this close to the election,” Murkowski said. “Sadly, what was then a hypothetical is now our reality, but my position has not changed.” The nine-member court has the power to hold presidents to account and rule on issues including abortion rights, gay rights and voting rights. A week after the election it is set to rule on a healthcare law that protects millions with pre-existing conditions. Trump has already appointed two justices but both were conservatives succeeding conservatives. A pick to replace Ginsburg could tilt the court right for decades, imperiling precedents such as Roe v Wade, the 1973 ruling that effectively legalised abortion. The current frontrunner for the vacancy is Amy Coney Barrett of Chicago, a federal appeals judge and the ideological opposite of Ginsburg. A Catholic and outspoken opponent of reproductive rights, Barrett was described by the New York Times as having “a rock-star reputation in conservative circles”. Another leading contender is Barbara Lagoa, an appeals judge in Atlanta. She is Cuban American and the first Hispanic woman appointed to the Florida supreme court. Either choice might rally conservatives wavering over Trump because of his behaviour and pandemic response. The struggle threatens to be among the most explosive Washington has seen for decades, stress-testing a system many see as broken and rattling a country already reeling from the coronavirus, economic collapse and a racial reckoning. McConnell has vowed to grant Trump’s pick a hearing. On Sunday he received backing from some prominent colleagues. Ted Cruz, senator for Texas, told ABC’s This Week “the right thing to do is for the Senate to take up this nomination and to confirm the nominee before election day”. Lindsey Graham, who chairs the Senate judiciary committee and previously said he would oppose filling a vacancy in an election year, pledged to support Trump in “any effort to move forward”. But if McConnell does hold a vote before the election, he will need to hold together at least 50 of his 53-strong caucus, aware Vice-President Mike Pence would break any tie. Having lost both Collins and Murkowski, the margin of error is wafer thin with Lamar Alexander of Tennessee, Cory Gardner of Colorado and Mitt Romney of Utah seen as potential obstacles. Democrats have limited options but could strike back quickly. If they win the White House and a Senate majority, they could expand the supreme court to from nine to 11 justices. Jerry Nadler, chairman of the House judiciary committee, tweeted: “If McConnell and Senate Republicans were to force through a nominee during the lame duck session – before a new Senate and president can take office – then the incoming Senate should immediately move to expand the supreme court.” Asked if Democrats might even move to impeach Trump or attorney general Bill Barr during a lame duck session, in a bid to stall the process, Nancy Pelosi, the House Speaker, told ABC: “Well, we have our options. “We have arrows in our quiver that I’m not about to discuss right now, but the fact is we have a big challenge in our country. This president has threatened to not even accept the results of the election with statements that he and his henchmen have made.” A new Reuters/Ipsos poll on Sunday found that 62% of respondents thought Ginsburg’s replacement should be chosen by winner of the election. But the issue will fire up both party bases. Democrats took in a record $91.4m in fundraising in just over 24 hours after Ginsburg’s death. Republicans hope this late plot twist could yet rescue Trump in an election where an NBC News/ Wall Street Journal poll on Sunday showed Biden leading by nine points, 51% to 42%.