The authors thesis is exactly the opposite of your conclusion. The author points to the big part of the nation and electorate that is completely fed up with the ancien regime and wants to destroy it. He posits that there is a floor of 40% of the electorate in that camp and it could go a lot higher than that after the failed impeachment attempt.
I agree when you think about 2016 Trump & Bernie were both the anti-establishment candidates that appealed to totally different ends of the spectrum. Proof that people are feed up with the Govt not representing and work for the people, rather working for itself. Truly a crying shame