US Supreme Court nominee Amy Coney Barrett faces a grilling by Democrats opposing her nomination, in day two of her Senate confirmation hearing.

They are likely to cast her as a threat to healthcare reforms passed under former President Barack Obama.

The conservative judge said on Monday she was “honoured” to be President Donald Trump’s pick for the top court.

Republicans are seeking to approve her nomination ahead of the presidential election in three weeks.

Her confirmation would give the nine-member court a 6-3 conservative majority, altering the ideological balance of the court for potentially decades to come.

Democrats fear Judge Barrett’s successful nomination would favour Republicans in politically sensitive cases that reach the Supreme Court.

She is the proposed replacement for liberal Justice Ruth Bader Ginsburg, who died last month aged 87.

But Republicans have praised Judge Barrett. Senate Judiciary Committee chairman Lindsay Graham on Monday said she belonged in “a category of excellence”.

“This is a vacancy that’s occurred, the tragic loss of a great woman. And we’re going to fill that vacancy with another great woman,” he said.

Republicans hold a slim majority in the US Senate, the body that confirms Supreme Court judges, making Judge Barrett’s nomination very likely to pass.

Democrats have criticised the rushed process as “reckless” and a “sham”, amid a coronavirus pandemic that has killed 215,000 people in the US.

They have also accused Republicans of hypocrisy. In March 2016, when Mr Obama, a Democrat, put forward a nominee to fill a spot on the court, the Senate Republicans refused to hold hearings, arguing the decision should not be made in an election year.

What’s in store for Tuesday’s hearing?
Judge Barrett will face the first of two days of direct questioning from senators on the deeply divided Senate Judiciary Committee.

It follows day one of hearings on Monday in which she explained her legal philosophy and qualifications for the lifetime position on America’s top court.

Democratic senators are likely to scrutinise her conservative views and decisions she has delivered as a judge on the Seventh Circuit Court of Appeals. Much of her record could be seen to be in opposition to the philosophy of the late Justice Ginsburg.

Healthcare is high up the agenda, amid the possibility that she could be a deciding vote to strike down reforms enacted by former President Obama, providing health insurance to millions of Americans.

The top Democrat on the committee, Senator Dianne Feinstein, argued on Monday that “Americans stand to lose the benefits that the ACA [Affordable Care Act] provides” if Judge Barrett is on the top court, when it hears a case against the public health insurance scheme next month.

“It’s beyond ironic that this administration, which has failed to respond to this pandemic, is rushing through a judge they believe will vote to strip away health protections,” Democratic Senator Chris Coons said.

Judge Barrett has in the past criticised a 2012 Supreme Court ruling upholding the ACA.

Republicans on the committee however praised Judge Barrett and defended the legitimacy of confirming the judge.

The hearings, lasting four days, are the key step before a full Senate vote on the nomination.

What did Judge Barrett say on Monday?
“I believe Americans of all backgrounds deserve an independent Supreme Court that interprets our constitution and laws as they are written,” the 48-year-old jurist, who is deeply religious and has conservative views on abortion, told senators on Monday.

Judge Barrett argued that elected politicians make “policy decisions and value judgments”, not Supreme Court justices.

“In every case, I have carefully considered the arguments presented by the parties, discussed the issues with my colleagues on the court, and done my utmost to reach the result required by the law, whatever my own preferences might be,” she said.

What’s the confirmation process?
After the hearings end, any committee member can require an additional week before the formal panel vote on whether to present the nomination for confirmation before the full Senate. It is not clear if the members will be able to vote remotely.

If she passes the committee stage, the full Senate will vote to confirm or reject Judge Barrett’s nomination.

Republicans already appear to have the 51 votes needed to get Judge Barrett confirmed.

Senate majority leader Mitch McConnell has vowed to hold a confirmation vote before the presidential election.

Barring a surprise, Democrats seem to have few options to prevent her from gliding through the Senate to the Supreme Court bench.