I'm always concerned whenever I watch episodes of "true crime" programs on television (Investigation Discovery, 48 Hours, Forensic Files, Dateline, etc.) which all too frequently feature cases in which the polygraph has been used in order to "determine" the guilt or innocence of suspects.
This type of coverage always places the polygraph and its use in an inevitably positive light, at least when it is employed for law enforcement purposes. :(
In addition, Maury and Dr. Phil use the polygraph for theater, presumably it helps ratings.
The gullibility and naivete of the American public contributes to the underlying support of the polygraph (infallible "lie detector"). The public wants to believe it having seen it on television shows, and Congress goes along with the American public.