The theme of "Drugs and Alcohol" in this novel is closely related to the theme "Transformation." Alcohol plays a big role in transforming protagonist Willie Stark into the enormous powerhouse he becomes. Based on all the drinking that goes on, you sure wouldn't know that All the King's Men is set during the period of American Prohibition. Though alcohol use is a theme in the novel, the novel doesn't seem to be making a specific argument on the morality of its use. Instead it seems to be commenting on the power of alcohol to change a person's personality.
By introducing Willie to alcohol, Jack helps create a monster.
In contrast to a story like John Updike's Rabbit Run, this novel makes a fairly positive argument for alcohol use.