They don't have a conscience like you or I. Here's one site's definition of sociopathy:
ANTISOCIAL PERSONALITY, SOCIOPATHY, AND PSYCHOPATHYsnip...
Sociopathy is chiefly characterized by something wrong with the person's conscience. They either don't have one, it's full of holes like Swiss cheese, or they are somehow able to completely neutralize or negate any sense of conscience or future time perspective. Sociopaths only care about fulfilling their own needs and desires - selfishness and egocentricity to the extreme. Everything and everybody else is mentally twisted around in their minds as objects to be used in fulfilling their own needs and desires.
They often believe they are doing something good for society, or at least nothing that bad. The term "sociopath" is frequently used by psychologists and sociologists alike in referring to persons whose unsocialized character is due primarily to parental failures (usually fatherlessness) rather than an inherent feature of temperament.
Lykken (1995), for example, clearly distinguishes between the sociopath (who is socialized into becoming a psychopath) and a "true" psychopath (who is born that way). However, this may only describe the "common sociopath", as there are at least four (4) different subtypes -- common, alienated, aggressive, and dyssocial. Commons are characterized mostly by their lack of conscience; the alienated by their inability to love or be loved; aggressives by a consistent sadistic streak; and dyssocials by an ability to abide by gang rules, as long as those rules are the wrong rules. As Stout (2005) indicates, it only takes three of the following to be defined as a sociopath, and some common sociopathic traits include:
Egocentricity; Callousness; Impulsivity; Conscience defect; Exaggerated sexuality; Excessive boasting; Risk taking; Inability to resist temptation; Antagonistic, deprecating attitude toward the opposite sex; Lack of interest in bonding with a mate
The site also says "the American Psychiatric Association estimates that 3% of all males in our society are sociopaths and Stout (2005) estimates 4% of the population."
I think they're all congregated in the GOP at the moment.