“Never doubt that a small group of thoughtful, committed, citizens can change the world,” Margaret Mead once noted: “Indeed, it is the only thing that ever has.” Thirty years ago today, a crowd of 200,000 protesters on Prague, Czechoslovakia ballooned to half a million people, a popular demonstration against that country’s Communist government, a “velvet revolution” that began the turn to a new parliamentary democracy. We at Public Seminar are humbled by that memory, and the power of people to demand change.

So let’s start with how change happens. Economist James K. Galbraith leads off our politics section this week with an analysis of Bernie Sanders’ economic platform: can Bernie do all these things? Read it and find out. Next, we turn to a reflection on activism, as Nick Estes interviews Native American historian interviews LaDonna Bravebull Allard, an enrolled member of the Standing Rock Sioux Tribe, who became an activist when the Dakota Access Pipeline threatened her homeland. Finally, political scientist David Forrest asks whether white progressives have become too invested in identity politics.

Next, we want to remind you about what hasn’t changed: the United States is holding more migrants and asylum seekers in administrative detention than ever before in history. Alex Aleinikoff is back this week to discuss the Trump administration’s attack on asylum policy at a moment when the global refugee population has reached 25 million souls – “the highest in a generation,” Aleinikoff notes. After this essay, you will want to reflect on the history of these cruel policies and what Americans have done to oppose them: Alexandra Délano Alonso discusses the sanctuary campus movement and John A. Lawrence explains how cities offering sanctuary to undocumented people were supported by the courts.

Finally, history is nothing more, or less, than change over time. This week, we want to reintroduce you to Past Present, a section of Public Seminar inspired by the history podcast. Twitterstorian Kevin Kruse leads us off with an interview about why doing the history of the recent past matters; Howard Jones reminds us, in a week when a whistleblower has triggered presidential impeachment hearings, that whistle blowers have moved history before. Three ordinary soldiers reported what they saw in the village of My Lai, in the Republic of Vietnam, on March 16 1968, and opened Americans’ eyes to what was being done in their name. Last but not least, senior editors Natalia Mehlman Petrzela, Nicole Hemmer, and Neil Young talk to New York Times Magazine writer Emily Bazelon about her new book on ending mass incarceration.

Claire Potter is co-executive editor of Public Seminar and Professor of History at The new School for Social Research. You can tweet with her @TenuredRadical.