In historical usage, white trash referred to an economically disadvantaged and uneducated white person who lacks manners and who has substandard living practices.
White people would often use the term as an insult toward other
white people. In modern usage, the term white trash has shifted and broadened to refer to any white person who harbors racist attitudes towards non-whites or minorities. It's often used as an insult directed at a white person regardless of the white person's
social standing, income, or education.