We forget: Johnson becomes president in 1963 based on an action that Tyler takes in 1841.

John Tyler’s a really complicated character because, on the one hand, he addressed the real vulnerability in the Constitution by being assertive and setting a precedent that held all the way through Lyndon Johnson. Looking back on all these vice-presidents, many of whom didn’t do so well in the top job, do you think that Tyler’s consequential decision ended up being the right way to go? When William Henry Harrison died a month after taking office, Tyler insisted that he be treated fully as the president, even though there was really no clear language on that question in the Constitution and there wouldn’t be a hard-and-fast rule until the 25th Amendment passed in 1967. I had no idea that John Tyler, who is so little remembered, was such a presidential-succession trailblazer. Intelligencer spoke with him about which veeps managed the transition to actual authority best and whether the job of vice-president even makes sense in 2019. In the book, Cohen, who has advised Condoleezza Rice and Hillary Clinton and is now the CEO of the technology company Jigsaw, explores the often-overlooked consequences of vice-presidential ascension, from Millard Fillmore’s pivot on the Compromise of 1850 to Harry Truman’s World War II decisiveness.

But as Jared Cohen makes clear in his new book, Accidental Presidents: Eight Men Who Changed America, some running mates who might otherwise have been consigned to the dustbin of history ended up changing the course of American history, for better - and in many cases worse - after their bosses died or were killed in office. From the beginning of American history all the way through Veep, the role of vice-president has often been mocked and ridiculed, even by vice-presidents themselves.

Book accidental presidents