On this edition of Your Call, Adam Jentleson discusses his new book, Kill Switch: The Rise of the Modern Senate and the Crippling of American Democracy. Jentleson says the Senate has become one of the greatest threats to US democracy.A tenacious minority of white conservatives are using the filibuster to block the majority from passing popular legislation. For much of its history, the filibuster was used to prevent civil rights legislation from becoming law. He says unless we drastically reform the Senate’s rules and practices — starting with the filibuster — we face the prospect of permanent minority rule.