I think the purpose of this book and the timing of its release are to smear Sarah and to keep these rumors alive until the election. A lawsuit will guarantee that it stays in the news that long. The Left seems to fear her that much!
However, the lies are such an overreach the whole gambit may backfire on them.
If she wants to run, this book doesn’t do a damn thing to her. Weirdos on the left fringe are not going to support her anyway.