WASHINGTON — If Congress confirms President Donald Trump’s nominee to succeed Justice Ruth Bader Ginsburg, the Supreme Court would become more conservative, and also perhaps more ready to tackle certain hot-button issues like abortion and guns. Chief Justice John Roberts would also likely become less able to steer the outcome in divisive cases.

Ginsburg, who died Sept. 18 at 87, was the leader of the liberal wing of the court, which had been split 5-4 between conservatives and liberals. Roberts had, on occasion, sided with the liberals. But if Trump fills Ginsburg’s seat, there will be six conservative justices, three of them appointed by him.

Here are several big issues that are poised to come before the justices where a more solidly conservative majority could make a difference:

Healthcare

A week after the presidential election, the court will hear arguments in bid by the Trump administration and Republican-led states to overturn the Obama-era health care law. In the midst of the coronavirus pandemic, coverage for more than 20 million people is at stake, along with the law’s ban on insurance discrimination against Americans with pre-existing medical conditions.

A more conservative court might be seen as more sympathetic to striking down the Affordable Care Act, but the court might still choose not to. The justices have less drastic options. For example, the court could invalidate “Obamacare’s” now toothless requirement that most Americans carry health insurance, and leave in place core provisions such as subsidized health insurance, Medicaid expansion and protection for people with medical problems.

Now that former President Barack Obama’s landmark law is more than 10 years old, its many provisions are fully baked into the health care system. Unwinding it would be a colossal undertaking, fraught with political risks.

President Donald Trump promised, but never delivered, a replacement.

Elections

Trump has said he wants Ginsburg’s replacement confirmed to the Supreme Court ahead of Election Day so that a full court can weigh in on any campaign-related litigation.

Speaking at the White House on Wednesday, Trump predicted the election “will end up in the Supreme Court, adding, “I think it’s important we have nine justices.” The 2016 election was conducted with only eight justices on the bench, however, after Republicans refused to hold hearings on President Barack Obama’s nominee to replace the late Justice Antonin Scalia.

It’s possible that an election-deciding case lands in the justices’ laps, as one did in the 2000 election between Republican George W. Bush and Democrat Al Gore. And liberals worry that a court with three Trump appointees would favor him in a dispute with Joe Biden.

But even if an election-deciding question doesn’t arrive at the justices’ doorstep, they have already weighed in on election changes states have made in response to the coronavirus pandemic. And more pre-election challenges are likely coming. So far this year the court has stopped other courts from altering election rules close to the election.

Abortion

Abortion rights advocates would seem to face insurmountable odds winning at the Supreme Court without Ginsburg.

Earlier this year, a divided Supreme Court struck down a Louisiana law regulating abortion clinics, reasserting a commitment to abortion rights. It was the first big abortion case of Trump’s presidency.

The 5-4 outcome turned on the vote of Roberts, who joined his four more liberal colleagues, including Ginsburg. The court addressed a law requiring doctors who perform abortions to have admitting privileges at nearby hospitals. The justices ruled that the law violates the rights established by Roe v. Wade, the 1973 decision that established a nationwide right to abortion.

But Roberts’ vote had to do with following court precedent rather than support for abortion rights. If a Trump nominee replaces Ginsburg, Roberts’ vote on the issue would likely become less decisive. And the addition of another conservative vote would likely spur states to test the boundaries of regulation.

Already, cases are headed to the court that would provide an opportunity to overturn or weaken Roe. v Wade. Those cases involve sweeping bans on abortions after six weeks or eight weeks of pregnancy.

Guns

The Supreme Court has for years been reluctant to take on new guns cases, but that could change under a more conservative court.

Last year, with two Trump justices aboard, the Supreme Court took on its first major gun rights case in nearly a decade. But the case ended with the justices sidestepping any major decision.

Gun rights advocates had hoped the court might use the case from New York City to expand on landmark decisions that established a right under the Second Amendment to keep a gun at home for self-defense. Instead, the justices ultimately threw out the case, citing changes in city restrictions and state law.

Three members of the court dissented, however, expressing concern that lower federal courts are not properly applying the court’s two big gun rights decisions from 2008 and 2010. Justice Brett Kavanaugh, who was among the justices who agreed the case should be thrown out, shared that concern, saying the court should address the issue soon.

Environment

After the president started pulling America out of the Paris climate accord, more than a dozen mostly Democratic governors were among those taking up the fight against climate-changing fossil fuel emissions themselves

A more conservative Supreme Court could doom those ongoing efforts, California Gov. Gavin Newsom said this week. Newsom said he’s “deeply anxious about what a 6-3 ideological majority on the court may mean to this conversation.”

But the outcome of the presidential election matters in this area too. A Biden administration could undo many of the dozens of Trump administration rollbacks weakening or eliminating many protections for the air and water and for people and wildlife.

Federal courts so far have rejected many of the rollbacks. Lawyers for environmental groups say if Trump were to win a second term and the makeup of the Supreme Court shifts significantly, they could be less likely to win if cases ultimately land there.