When performed by an employee in an exchange for pay, a job consists of duties, responsibilities, and tasks (performance elements) that are (1) defined and specific, and (2) can be accomplished, quantified, measured, and rated. From a wider perspective, a job is synonymous with a role and includes the physical and social aspects of a work environment. Often, individuals identify themselves with their job or role (foreman, supervisor, engineer, etc.) and derive motivation from its uniqueness or usefulness.
Trump runs a few enterprises that employ hundreds of people and pay millions of dollars in Federal taxes that McCain helps spend to the tune of Trillions of Dollars. IOW, Trump is useful and McCain is not.