ith the Senate poised to quickly confirm Amy Coney Barrett to replace the late justice Ruth Bader Ginsburg, the Supreme Court will soon operate with a stout 6-3 conservative majority, rather than with the slimmer 5-4 conservative majority it has recently had. A one-vote shift may appear incremental, but it’s a shift that could have seismic consequences for the country.

A relative 5-4 balance has meant that neither bloc could dominate, because a move by one conservative justice to the liberal side in a given case could swing the outcome. That sometimes led the justices to broker compromise positions on thorny issues, or to avoid taking up certain matters altogether if they weren’t sure whether all of their colleagues would vote along ideological lines. If the president’s nominee is confirmed to fill Ginsburg’s seat, however, the court’s conservative bloc will be able to afford to lose a vote and still prevail, reducing the need for narrower decisions, compromise and forbearance.

Chief Justice John G. Roberts Jr. — appointed by President George W. Bush in 2005 — has functioned as the swing vote, occasionally siding with his liberal colleagues, sometimes to maintain the court’s veneer of institutional nonpartisanship. With six justices cementing a conservative majority, liberals who hope to prevail on issues that divide along ideological lines will have to persuade Roberts and another of the court’s conservatives (three of whom will be Trump nominees).

Roberts was the swing vote in the 2012 decision to uphold the Affordable Care Act. But a new challenge to Obamacare is slated for the upcoming court term, which will begin next month, and if a new justice has been seated, the court’s three remaining liberals may not be able to save the statute. In theory, the case is narrowly about the constitutionality of the ACA’s individual mandate, but if the court finds that the mandate is “inseverable” from the rest of the legislation, the new majority could bring down the entire law — an explicit goal of Republicans, including Trump, since Obamacare’s inception.

The biggest target for conservatives is Roe v. Wade. As a candidate, Trump promised to nominate justices who would overturn the landmark 1973 decision, which legalized abortion nationwide. On this point, at least, he has been true to his word. Last term, Trump’s first two Supreme Court nominees, Justices Neil M. Gorsuch and Brett M. Kavanaugh, voted to uphold a Louisiana law requiring abortion providers to maintain hospital admitting privileges, even though, four years ago, the court had invalidated a similar law in Texas, protecting women’s right to access abortion. Once again, Roberts was the deciding vote, joining the liberals to strike down the Louisiana law. But a third Trump justice — presumably one disposed to vote like Gorsuch and Kavanaugh — could solidify the court’s anti-choice bloc. Even if Roe isn’t immediately overturned, a stronger conservative majority could let stand other abortion restrictions that come before the court, including bans on certain procedures or abortion after 12 weeks of pregnancy.

But reproductive rights are not limited to abortion. Last term, in Trump v. Pennsylvania, the court heard a challenge involving the ACA’s mandate that insurers cover contraception, holding that the Trump administration had the legal authority to exempt employers from the mandate. The court did not determine whether the administration’s regulation satisfied all of the procedural rules or whether a future administration could roll back the exemption and require insurers to provide coverage even if an employer has religious or moral objections to contraception. If either of those issues come before the court again, it will be Ginsburg’s voice, as much as her vote, that will be missed: Although she was in a hospital bed when the court heard oral arguments, her displeasure at having to revisit women’s access to contraception was evident. In her dissenting opinion, she chastised the court for leaving “women workers to fend for themselves” and casting “aside countervailing rights and interests in its zeal to secure religious rights to the nth degree.” Despite this, Gorsuch and Justice Samuel A. Alito Jr. concluded in their concurring opinion that Congress cannot require employers to provide women with insurance coverage for contraception. With Ginsburg gone, their view may prevail, throwing up a roadblock for any future administration or Congress to expand access to contraception.

The change brought by a 6-3 conservative majority would radiate beyond reproductive rights or access to health coverage. It would affect issues at the heart of a functioning democracy and government — positioning the GOP to maintain its grip on political power at the expense of democratic principles and preventing historically disenfranchised groups from accessing civic institutions.

In Shelby County v. Holder, the court did away with the Voting Rights Act provision that required states to clear potentially discriminatory changes to their election laws with the Justice Department, with Roberts concluding that “our country has changed” since the legislation was passed. With another vote, conservatives might move to invalidate what remains of the act, including Section 2, which provides for restrictive voting laws to be struck if they result in discrimination, with or without intent.

The new court could also greenlight the Trump administration’s plan to exclude noncitizens from the census and from congressional apportionment, which would further entrench Republican political power. In 2019, a 5-4 majority, with Roberts and Ginsburg in the majority, rejected the Commerce Department’s rationale for adding a citizenship question to the census. This summer, the president responded by directing the commerce secretary to exclude noncitizens from the census count, which will be used to determine how many congressional seats each state receives. A three-judge court invalidated the president’s proposal, but a different outcome is foreseeable if the question reaches a 6-3 Supreme Court.

Although in the abstract, the court unanimously affirmed the “one person, one vote” principle in 2016, it did not find that states are required to draw legislative districts based on the number of people, rather than the number of citizens. Just this week, Alabama asked the courts to fast-track a case that could answer that question. If the issue comes before a 6-3 Supreme Court, the court could say both that states can exclude noncitizens when they draw legislative districts, and that states can create districts with vastly different numbers of people in them. Either conclusion would allow Republican legislatures to overrepresent traditional Republican strongholds and underrepresent Democratic-leaning areas. States could make political representation even more unequal and undemocratic if the new court prohibits citizens from adopting independent redistricting commissions, which take the task of legislative redistricting out of the hands of self-interested lawmakers. A bare majority of the court approved independent redistricting commissions in 2015, with Ginsburg and Justice Anthony M. Kennedy in the majority. Now that both of those justices are no longer on the court, the conservatives could revisit that opinion.

A more conservative court would be poised to exempt religious objectors from complying with statutes that prohibit discrimination against racial minorities, women, the disabled, religious minorities and the LGBT community. This could mean that, although marriage equality is the law of the land, those who object to same-sex marriage on religious grounds may refuse to serve LGBT couples or employ LGBT workers — and could claim exemptions from anti-discrimination laws. In the upcoming term, the court will decide whether cities, as a condition for receiving a government contract, may require a religious entity to comply with anti-discrimination laws.

The last time affirmative action was before the court, a bare 4-3 majority (Justice Elena Kagan was recused and the late justice Antonin Scalia’s court replacement had not been seated), in which Ginsburg joined, upheld race-conscious university admissions policies as a way to further diversity. With a 6-3 conservative majority, the court could overturn decisions that ensure that racial minorities have equal access to elite academic institutions.

A more conservative court could refashion the regulatory state by reviving the “nondelegation doctrine,” restricting Congress’s ability to delegate authority to administrative agencies. Such a shift would change government as we know it, preventing agency regulations aimed at combating climate change, delivering health care or addressing a global pandemic. It isn’t a stretch to say that decision-making along these lines would mean “most of Government is unconstitutional,” as Kagan has put it.

These scenarios don’t even encompass the very real possibility that a 6-3 court could be called on to resolve a contested presidential election this year. If Trump’s nominee is confirmed, a third of the court will have been chosen by him, and they will be asked to ensure his victory.

For Trump, Senate Majority Leader Mitch McConnell (Ky.) and the Senate’s Republican majority, the high court is key to securing broad power for which there is no democratic mandate. Faced with the prospect of Republican minority rule, many congressional Democrats have suggested that they’re keeping their options open, including the constitutionally permitted possibility of adding more justices to the court — “packing” it — to better reflect popular will. They may be too late: With a 6-3 conservative bloc in the offing, and the lower federal courts freshly stocked with Trump appointees, the Republicans’ own court-packing plan is already well underway.

Twitter: @LeahLitman