Is, The Plot Against America, a good book and why?

Answer 1

Yes, it is. Philip Roth is a major American author, and always interesting even when not at his best (And even when you take issue with one or another of his beliefs / attitudes.)

The book is well-written, and interesting in part for the way it combines a science-fiction staple (alternate history: The US, following Charles Lindbergh, sides with Hitler) and combines it with closely remembered and depicted details of suburban life in New Jersey at that time. Roth is known for issues of sexual relations and American Jewishness, but much of what he writes about is family life.

It is also worthwhile to be reminded that a significant portion of the US was sympathetic to Hitler, at least at the beginning, including the US hero Lindbergh.