Hovering over the main debates of this election—immigration, health-care reform, race, criminal justice—is a meta-issue: the make-up of the federal courts. Rulings over the last few years leave no doubt that the Supreme Court (and the other federal courts) can affect all of these issues and many others. It’s no wonder then that one of the major topics the candidates are arguing about is the Court itself. And rightly so—what voters do this November will effectively decide who sits on the Supreme Court and the lower federal courts, and that in turn can influence much else at stake in this year’s election, and not just for the next four or eight years.

Because of issues such as abortion, affirmative action, and religion, the make-up of the courts has long been a rallying cry for conservatives. But this year, the courts are part of the conversation for progressives, too. This is, in part, because Republican Senators’ unwillingness to consider President Obama’s nominee to fill the Supreme Court vacancy created by Justice Antonin Scalia’s death means that the next President might end up filling that empty seat. Indeed, both presidential nominees referenced the importance of the Supreme Court in their convention speeches. And, given that three of the current justices are in their late 70s or early 80s, there will likely be additional openings on the Supreme Court for the next President to fill.

The future of the lower federal courts is at stake as well, and although those courts receive less attention than the Supreme Court, they shouldn’t. After all, virtually every case that makes its way to the Supreme Court starts in the lower courts. Indeed, the lower courts decide thousands of consequential cases each year that never make it any higher. Right now, there are nearly 100 vacancies on the lower federal courts, and more vacancies will surely continue to open up.

The next President’s appointments will thus shape the trajectory of the federal courts for decades to come. The Supreme Court in particular is at a major transition point. After decades with a solidly conservative majority (albeit with some members who take turns joining the Court’s relatively progressive wing just often enough to keep things interesting), the Court could be on the verge of having a majority of progressive Justices for the first time since the early 1970s. The potential consequences of such a shift are significant.

Over the past several decades, the Court has consistently moved the law to the right in a host of different areas, from race to voting, campaign finance to access to the courts. A Court with a more progressive majority might well start moving the law back.

For example, consider voting rights. In 2013, the Court, led by Chief Justice John Roberts, invalidated by a 5-4 vote a key provision of the Voting Rights Act, one which required states with a history of voting discrimination to clear any changes in their election laws in advance with the Department of Justice or a federal court. While it’s unclear whether a Court with a progressive majority will have the opportunity to weigh in on that specific decision in the near term, it could ensure that other provisions of the Voting Rights Act are interpreted in a sufficiently robust fashion to help address the problems caused by the Court’s initial decision. And with multiple challenges to voter-ID laws and other changes to election laws working their way through the lower courts, the Court could have an opportunity to weigh in on these issues shortly.

Or consider the issue of campaign finance. The Supreme Court’s 2010 decision in Citizens United has been one of the most discussed topics in the campaign to date. With the prospect of a Court that is less hostile to campaign finance regulations, states and localities may well begin to pass ordinances designed to give the Court an opportunity to cut back on campaign-finance limitations, as St. Petersburg, Florida recently did.

Finally, consider access to the courts. In a series of closely divided decisions, the Roberts Court has repeatedly limited access to the courts—restricting who has the right to sue, forcing individuals into arbitration instead of courts, and making it more difficult for individuals with small claims to band together by bringing class actions. A Supreme Court with a solid progressive majority could cabin these precedents and ensure that the federal courts are able to serve their purpose in our constitutional structure—that is, as a forum in which individuals can vindicate their rights. Indeed, this coming term, the Court is already scheduled to hear a case about whether cities can sue banks when they engage in predatory lending practices that target racial minorities. Other cases involving class actions and arbitration will surely work their way up to the Court soon.

And a Court with a solidly progressive majority could do much more. It could continue to strike down unconstitutional laws that limit a woman’s right to choose. It could recognize the role race continues to play in our society and take account of that reality in a host of areas, including criminal justice. It could limit recent decisions that have boldly and erroneously interpreted the First Amendment in a way that allows corporations to use it as a shield against government regulation. It could embrace the framers’ vision of a robust federal government that has the power to address national problems.

And consider the alternative. What if after this election there’s an even more solidly conservative majority than there has been, and the most progressive of the Court’s conservatives is not Justice Anthony Kennedy, but instead Chief Justice John Roberts or Justice Clarence Thomas? That hypothetical Court could eliminate all campaign finance regulations. It could overrule Roe. It could eliminate affirmative action. It could twist the Constitution’s guarantee of religious liberty to limit the rights of LGBTQ Americans to equal protection under the law. And it could make it impossible for progressive presidents down the line to use their authority under existing law to take executive action to address urgent problems in areas ranging from climate change to immigration.

The federal courts may not always be the focus of the American populace, but those courts’ decisions affect Americans every day. This election year, more so than most, that empty seat on the Supreme Court makes clear just how high the stakes are.