An online playbook seems to be emerging around some of the political conversations taking place: someone says something deemed offensive or troubling, social media goes into a frenzy, and that person is effectively “cancelled.” An open letter recently published in Harper’s Magazine argues that this threatens free speech. The letter’s co-author, Thomas Chatterton Williams, joins the program.

The film "Radioactive" portrays the life of Marie Curie, the first woman to win a Nobel Prize -- with her husband Pierre -- for discoveries in radioactivity. Faced with a succession of obstacles as a female scientist, she went on to win a second Nobel in her own right. Christiane speaks with the film’s director, Marjane Satrapi, who came to prominence with her graphic novel memoir "Persepolis."

The presidential election is just over 100 days away, and the race is increasingly dominated by two issues: coronavirus and the reckoning over racism. Joe Biden is forging a remarkable bond with his main rival for the nomination, Sen. Bernie Sanders, who says Biden could be the most progressive president since FDR.

Results from Oxford University suggest a vaccine that researchers are developing there is safe and can produce immune responses. But these findings come amidst a fumbled pandemic response by the UK government, as the country reaches the second highest death rate in Europe. Professor Devi Sridhar is chair of global public health at the University of Edinburgh and discusses the country's response.

In the U.S., coronavirus continues to surge, bringing the total number of confirmed cases to over 3 million – the highest in the world. Meanwhile, anti-racism protesters and federal troops continue to clash in Portland, Oregon. Maryland’s Republican Governor Larry Hogan has been sharply critical of President Trump’s handling of the coronavirus and crises. He joins the program to discuss all this.

Georgia’s governor, unlike Maryland's, is on the same page with President Trump. In fact, Governor Brian Kemp is going so far as to sue the mayor of Atlanta to block the city’s mask mandate. Democrat Keisha Lance Bottoms was elected in 2017 and is reportedly on Joe Biden’s short list as a potential running mate. She speaks with Walter about all this, and why she opposes defunding the police.

Today the UK suspended its extradition treaty with Hong Kong and banned the export of any riot control equipment to the territory. The reason for this about-face from one of the West’s most China-friendly nations is a new national security law imposed on Hong Kong by Beijing that criminalizes most political dissent in the territory that once belonged to Britain. Activist Nathan Law responds.

In contrast to pro-democracy voices, defenders of a new national security law in Hong Kong say it’s a necessary step to stop chaos and disorder. Barrister Alan Hoo, a vice chairman of Hong Kong’s pro-Beijing Liberal Party, joins the program.

Georgia Congressman John Lewis died aged 80 on Friday after a lifetime spent fighting for racial equality and social justice. House Majority Whip James Clyburn was a close friend of Lewis, and joins the program to honor his friend.

Democratic presidential nominee Joe Biden's choice of running mate is the subject of mounting speculation. Zerlina Maxwell argues that it should be one of the many qualified Black women in politics today. She speaks with Michel Martin about her new book "The End of White Politics," and explains how the Democrats’ failure to focus on communities of color could be their downfall.

The political fight over children returning to school this fall continues to rage, and now the medical community is weighing in, with the American Academy of Pediatrics issuing its own guidance. Dr. Sean O’Leary is vice chair of the organization’s committee on infectious diseases. He joins Hari Sreenivasan to explain how children are affected by the virus and the challenges of reopening schools.

As a student, civil rights activist John Lewis led sit-ins to end segregation in Nashville and marched alongside Martin Luther King, Jr. in Selma – where he was brutally beaten while peacefully protesting for his right to vote. Today, the 17-term congressman from Georgia is known as the “conscience of Congress." Filmmaker Dawn Porter joins the show to discuss her portrait of his amazing life.

Many blame Brazil’s President Jair Bolsonaro for the country’s two million coronavirus cases and nearly 77,000 dead. Despite having contracted the virus himself, Bolsonaro continues to downplay its risks, dismissing it as a “little flu.” Petra Costa is a Brazilian filmmaker whose award-winning documentary "The Edge of Democracy" warns of a threat to Brazil’s democracy even beyond the pandemic.

How did governments and institutions fail to heed the warnings, to learn from the past, to act on those lessons and to prepare for the pandemic? Bestselling author and economist Tim Harford has written extensively about these issues, which he also addresses in his podcast series “Cautionary Tales.” He joins the program from Oxford.

Australian comedian Hannah Gadsby has redefined what's acceptable in stand-up comedy. By mining the depths of her own past, she creates a bracingly honest comedic experience that speaks out about homophobic and sexual violence. She joins Christiane to discuss her latest stand-up special “Douglas."

Data show that the median white family has 10 times more wealth than the average black family, a fact familiar to law professor Mehrsa Baradaran. In her book, “The Color of Money: Black Banks and the Racial Wealth Gap,” she examines how Black communities have been systemically shut out of the banking system. Michel Martin spoke with Baradaran about these issues--just before the pandemic.

The president doesn't have to look across the aisle for opponents. Groups like Republican Voters Against Trump are trying to convince party members to abandon the president. And it could be working: a poll shows Trump trailing Biden in Pennsylvania, a state that was key to his 2016 victory. Christiane speaks about this with Sarah Longwell, a Republican hoping to making Trump a one-term president.

Christiane speaks with two mayors whose cities are at different ends of this coronavirus pandemic: from Milan is Mayor Giuseppe Sala, chair of the Global Task Force – his city is gradually recovering after Italy became the European epicenter of the disease – and from New Orleans is Mayor LaToya Cantrell. Her city is currently closing down bars once again as coronavirus cases surge.

As the debate rages over how and whether to reopen schools and universities, few are better placed to assess this dilemma than Janet Napolitano. She is the first female president of California’s sprawling public university system, and was also the first female secretary of homeland security under President Obama. She speaks with Walter Isaacson about what her university is doing to help students.