The Senate is where Joe Biden\u2019s agenda will live or die. More specifically, the intricacies of archaic Senate rules \u2014 the budget reconciliation process, the filibuster, the majority leader\u2019s ability to control the floor \u2014 combined with the fealty today\u2019s senators have to yesterday\u2019s structures will decide the agenda\u2019s fate. It would be the gravest mistake for progressives, or anyone else, to consider the fight over how the Senate works to be a sideshow compared with debates over a $15 minimum wage, a Green New Deal or democracy reform. The fight over how the Senate works is what will decide all those other debates.\n\nAdam Jentleson served as deputy chief of staff to Senator Harry Reid when he was the majority leader. Jentleson was high enough to see how the institution really worked, and young enough to be free of gauzy nostalgia from the days of yore. And his book, "Kill Switch: The Rise of the Modern Senate and the Crippling of American Democracy," is both blistering and persuasive. \u201cThis is not a particularly uplifting history,\u201d Jentleson writes. But nor is it without hope. \u201cUnlike many of the structural features that determine the politics of our era, the Senate is relatively easy to reform.\u201d\n\nSo I invited Jentleson on my podcast, \u201cThe Ezra Klein Show,\u201d to explain how the modern Senate really works, why it works that way, and how to fix it. Along the way, we discuss what can \u2014 and crucially can\u2019t \u2014 be passed through budget reconciliation, why senators like Joe Manchin and Kyrsten Sinema continue to defend the filibuster (and why Jentleson thinks they will change their minds), the foundational myths of the Senate, like the idea that the modern filibuster encourages compromise, how Mitch McConnell understands the American political system better than his opponents and much more.\n\nRecommendations:\n\n"Double Indemnity" by James Cain\n\n"Master of the Senate" by Robert Caro\n\n"The Sum of Us" by Heather McGhee\n\n"Where the Wild Things Are" by Maurice Sendak\n\nYou can find transcripts (posted midday) and more episodes of "The Ezra Klein Show" at nytimes.com/ezra-klein-podcast, and you can find Ezra on Twitter @ezraklein.\n\nThoughts? Guest suggestions? Email us at ezrakleinshow@nytimes.com.\n\n\u201cThe Ezra Klein Show\u201d is produced by Rog\xe9 Karma and Jeff Geld; fact-checking by Michelle Harris; original music by Isaac Jones; mixing by Jeff Geld.