Barton Swaim, who wrote the review, thinks that the authors of Fault Lines are essentially left-leaning political hacks who blame the Republicans for everything. I haven't read Fault Lines, so I don't know, but I think we should probably attribute responsibility for our situation more or less equally as between the political parties.
In addition, I am not as interested in "how we got here?" as I am in "how the heck do we get out?"
As our government remains shut down, precisely because Americans (or at least their elected representatives) are so embittered and divided, how we bridge that yawning gap between the parties strikes me as the real question.