Welcome back to The Monkey Cage’s weekly presentation of Founding Principles, short videos designed to explain U.S. government and how it works — in theory and in practice. We started by looking at the structure of the government (Congress, the presidency and the courts) and then at public opinion, the media and elections — both the structure of our electoral system and voter behavior — as well as citizens’ political involvement. For several episodes now, we’ve been talking about policymaking, including the legislative process, putting policies into action through bureaucracy and how the civil liberties in the Bill of Rights shapes U.S. policy goals.

So now let’s think about the close partner of civil liberties: civil rights, including the right to vote and to be free from unjust discrimination. When we think about civil rights, we tend to think about marches and movements and martyrs. That’s an important piece of the story. But many kinds of people have pushed us to take a broader view of the Declaration of Independence’s brave claim that “all men are created equal.” A quick spoiler: All increasingly means all. And not just men.

This episode traces that trajectory. The inspirational prose of the Declaration jarred from the outset with the Constitution’s protection of slavery. Even so, what Martin Luther King would later call “those majestic words” were embedded in the American psyche, prompting more than two centuries of efforts to close the gap between our ideals and our institutions. From Jim Crow to Plessy v. Ferguson to Brown v. Board of Education to the Voting Rights Act, it’s been a moral struggle, a legal struggle, often a violent struggle, and continues today. Over time, de jure discrimination and segregation — that which is allowed or even required by law — has diminished greatly. But de facto discrimination, rooted in people’s thoughts and feelings and emerging in behavior, is far harder to root out — something the civil rights movement found out when it moved from the Southern states to the Northern cities.

For generations, women, too, have been pressing for equal rights. In 1908, an all-male Supreme Court could declare that “as healthy mothers are essential to vigorous offspring, the physical wellbeing of woman becomes an object of public interest and care in order to preserve the strength and vigor of the race.” But in 1995, it was Justice Ruth Bader Ginsburg who wrote the majority opinion rejecting Virginia’s plan to set up a separate military academy for women. Separate but equal could not be justified here, either, the Supreme Court held.

More recently, we have seen a push for the rights of LGBT citizens. As recently as the mid-1980s, the Supreme Court held that laws punishing same-sex intimacy were constitutional. But determined efforts to change public opinion drove rapid change. In 2013, the court ruled that the federal government could not override state-level decisions to recognize same-sex marriage. And in 2015, it held that states could not ban such unions, either.

That 5-to-4 decision was controversial. So are many of today’s most important conversations. What happens when religious freedom and civil rights collide? What sort of scrutiny is required to treat groups differently under the law — whether to hurt or help them? Many of the debates over rights and equality these days have moved from our courtrooms to our classrooms and our living rooms. It’s not just in the history books but in the headlines as well.