Derek Monson recently wrote about the U.S. Supreme Court’s decision in Dred Scott v. Sandford. That decision, one of the few pre-Civil War decisions to strike down a federal statute, arguably contributed to the Civil War.

The most prominent critic of the decision was Abraham Lincoln, then running for a Senate seat in Illinois. Lincoln took his opponent, incumbent Stephen Douglas, to task for his defense of the decision. In a Chicago speech, Lincoln even characterized Douglas as treating the decision as sacred. To Lincoln, that treatment was unjustified.

While he accepted the proposition that the Supreme Court could “indicate to the public how other similar cases will be decided when they arise,” he argued that the court’s “decisions are of greater or less authority as precedents, according to circumstances.”

In a way, Lincoln’s position did not prevail. We are accustomed now to thinking of court decisions as absolutely final. Rather than debating whether a particular decision is authoritative, opponents of a decision will seek to change the legal provision on which that decision was based, or even the makeup of the court, to get a different decision.

The role of Supreme Court decisions as precedent for future cases, then, is quite firmly settled and helps explain why these decisions are so significant.

This significance is most evident in the way lower courts treat Supreme Court decisions. For the federal district courts and courts of appeals, Supreme Court decisions are binding and must be followed in cases that raise the same legal issues. So, when the Court decides a case, it is directly shaping the result in other disputes that follow.

To illustrate how this works, consider three recent lower court decisions involving issues the Supreme Court previously addressed.

In A.H. v. French, parents in Vermont challenged a state law that gave education vouchers to students in towns without public schools. The vouchers were available to students who were home-schooled or in public or secular private schools but not those in private religious schools. This policy is similar to one the Supreme Court held was invalid in Espinoza v. Montana Department of Revenue – a rule that denied to students attending religious schools scholarship funds available to students attending other schools. The federal district court in Vermont determined that because of the Espinoza precedent, the Vermont rule was unconstitutional. The U.S. Court of Appeals for the Second Circuit agreed, noting the state had “continued to discriminate against religious schools and students in violation of the First Amendment.” It enjoined the state from continuing to enforce the provision.

In Starkey v. Roman Catholic Archdiocese of Indianapolis, a guidance counselor whose roles included “facilitate[ing] faith formation,” challenged her termination as an employee of a Catholic hospital which she alleged was caused by her same-sex marriage. The school responded that the counselor was a ministerial employee responsible to promote Catholic teachings and therefore the courts could not consider her claim without unconstitutionally interfering with the religious mission of the school. An Indiana district court determined its decision in favor of the school was compelled by the Supreme Court’s decision in Our Lady of Guadalupe School v. Morrissey-Berru. Morrissey-Berru held that a teacher in a Catholic school could not bring a lawsuit to challenge the termination of her employment in a ministerial role.

The Court’s precedent does not always result in victories for religious organizations. In Hammons v. University of Maryland Medical Services Corporation, a district court in Maryland applied the Supreme Court decision in Bostock v. Clayton County. The holding of Bostock was that the prohibition of sex discrimination in federal discrimination law included an unwritten prohibition on sexual orientation and gender identity discrimination. In Hammons, a transgender patient denied an elective hysterectomy by a Catholic hospital alleged sex discrimination. Following Bostock, the district court said the hospital’s denial violated the anti-discrimination provision in the Affordable Care Act.

Even though the Supreme Court does not resolve a large proportion of the cases that are presented to it, the decisions it does issue reverberate to affect many other disputes through the principle of precedent. Its decisions on a handful of cases can, over time, expand and contract the rights of the entire nation.