What is the theme in The Runaway Jury by John Grisham?

One of the main themes running through The Runaway Jury is that of power and its corruption. Throughout the novel power is achieved through wealth and stature, which can be used to influence or pay anyone off. The reader sees this primarily through the Big Four, who, although they are actually competing companies, come together to be a strong force against the anti-tobacco legislation. They use their collective wealth to carry out elaborate schemes to influence and sway the votes of jurors and their families, and their size is used to influence government organizations or anyone who gets in their way.