This book read something like "Politics I've Heard Of: The Middle Years," since most of my '60s reading has been on the grassroots stuff like SDS and the Black Panther Party, and most of my politics reading was either more WWII-adjacent or more recent. We see the end of the careers of a number of the WWII people, and either the start of the careers of the recent people, or the parents of the more recent people (Hi, Mittens!). Plus it covers an awkward growing period in politics where the presidential candidate selection process was neither fish nor fowl, and TV was just becoming fully integrated, and oh yeah, there was a war on.
The style is chatty and skims a lot of detail (noticeable when we hit area's I'd covered elsewhere). The author read his own audiobook, which he did well, often doing credible impressions of the various players making speeches and never droning (and certainly not debasing my impression that he was fond of his own voice). His portraits of the personalities of the politicians involved seems pretty solidly researched (mentions of Caro for LBJ, for example), and he uses a lot of transcripts and speeches when he can. I'd be interested to see a paper copy for the end notes.
The three claims of the book are that the 1968 election was one of the zaniest in US history and that the story is worth telling on those grounds; that decisions and outcomes of the election permanently changed the way US elections were run on a number of levels and transitioned the electoral system from the WWII era to more or less the shape it currently takes, and finally that even though the peace ticket failed it helped end the Vietnamese-American War. There are also minor points about continuity with the 2016 election that one feels the author couldn't resist.
I would say that well it's a story worth telling, and was certainly entertaining, the zaniest election prize is a hard one to hold. Almost all of the elections before, during and after the US Civil War could probably give it a run for its money, and the 1868 Johnson-Grant election would beat the pants off it when it comes to flat out odd. How many times has a sitting president run for election on the opposing party's ticket? The transition argument is more convincing, and probably some of the most interesting sections of the book were to do with how completely different the electoral system was fifty years ago, and how that changed how politics were played, as well as the evolution of television advertising and coverage and the impact of protests. The argument that Gene McCarthy's run as a peace candidate against a sitting president in his own party legitimised the anti-war protests with the political mainstream and helped end the Vietnam war isn't really well laid out. One can tell that O'Donnell sees a lot of himself in McCarthy (a fellow Catholic), and hates to say it was all for nothing, or perhaps even ensured that Nixon got in and extended the war. That made me roll my eyes at the conclusion section a bit, but didn't ruin the book.
From my perspective, the book is most interesting on the grounds of an entertaining story, and it holds that pretty well. Bobby Kennedy, LBJ and especially Gene McCarthy hold down the flawed and often tragic hero roles; Nixon is, as always, history's most convincing villain, and there's enough plotting and scheming to fill an epic fantasy trilogy. Would rec if you're interested in more or less the establishment side of the period, be it a liberal one, and lots of gossip and plotting.