Both arise out of a minority of the population that feels oppressed, devolving into extensive categorization and generalization.

Both have a vile hatred and resentment towards the opposite end of the spectrum, particularly out of personal resentment and bias.

Both are blind to their own lack of self-awareness and base their ideas and motives off of rhetoric and seemingly "rational" ideas that appeal to their subjectively-oriented minds.

Both do not necessarily believe in the true merits of their own ideologies but pick and choose which of its values apply to their own personal morals and goals in life.

Both are driven out of an unfortunate insecurity or feeling of inferiority due to environmental and biological forces.

Both make valid arguments in some areas which become overblown through group polarization and ultimately become twisted into irrational, biased nonsense.

Both cite pseudo-science as evidence for their particular claims, in addition to misrepresenting and misquoting famous psychologists, historians, and philosophers to further their own set of beliefs.