Twitter's decision Friday to join Facebook in permanently suspending President Trump's account underscored the fundamental role of social media in one of the most tumultuous periods in American history. If it feels strange and unusual, that's because there's no historical precedent, neither in media nor the presidency.

"This has not happened before," says Margaret O’Mara, a historian, author and University of Washington professor, our guest commentator on this week's show.

"Particularly in the modern period, what the president says and does has always been covered, because it's always been newsworthy," said O'Mara, who specializes in the history of tech and politics. "Particularly as the presidency grew into becoming the most important job on the planet, and the U.S. was becoming a military and economic superpower, what the president said mattered -- it had credibility."

We also discuss the future of Seattle, Silicon Valley and other established tech hubs in the aftermath of the pandemic, a topic of O'Mara's recent New York Times opinion column, "California May Lose Some of Its Stars. But Silicon Valley Is Forever."

And we wrap the show with highlights from O'Mara's bookshelf: "Uncanny Valley," by Anna Wiener;"Race for Profit: How Banks and the Real Estate Industry Undermined Black Homeownership," by Keeanga-Yamahtta Taylor; and "The Cigarette: A Political History," by Sarah Milov.

Produced and edited by Curt Milton. Theme music by Daniel L.K. Caldwell.

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