The Ideological Left rests entirely upon Relativism.
Relativism is the doctrine which holds that knowledge, truth, and morality exist only in relation to one's cultural, societal, historical and personal context, and, as such can never be the result of soundly reasoned moral absolutes.
It is through this deviation in reason that relativism axiomatically rejects the objectivity which is essential to truth.
And with truth being essential to trust and, both of those being critical to the establishment of a soundly reasoned morality, and because a soundly reasoned morality is essential to Justice... it becomes clear to reasonable people, that Relativism can never serve justice.
Therefore, absent any since of truth, no trust all resting in amoral immorality... with absolutely no means to know what justice even look like... there is nothing LEFT: but HATE!