Nixon? Try Cops and Robbers.
Reaganism? Try Drowned Hopes.
Neoliberalism? Try What's The Worst that Could Happen? or The Ax.
The first chapter of The Ax can be read here. I recommend it as a good place to enter the Westlake books. It is a spare and approachable novel driven by the same humanist aesthetic as Chaplin's Monsieur Verdoux.