This may not be the answer you are looking for, but the central personality trait associated with egalitarian leftist politics in general is Big 5 Agreeableness, particularly the subtrait Compassion. The problem with that is Compassion is likely derived from the mother-infant relationship and thus has a tendency to divide the world into helpless infants (potential victims) and predatory snakes (oppressors). Furthermore, the most hardcore egalitarian left wing activists, in addition to being high in Compassion, are often very high in Big 5 Conscientiousness, particularly the subtrait Orderliness (which is, ironically, often associated with religion, puritanism and right wing politics). This is a problem because normal egalitarian leftists, with their high Agreeableness, don’t want to hurt or be seen to hurt anyone. Highly Agreeable people also have some conformist, don’t-rock-the-boat tendencies, which means they often have a hard time standing up to the Orderly types in their own coalition. And, as noted before, Agreeable people tend towards a Manichean division of the world.
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If you are an high Compassion egalitarian leftist who is also very high in IQ, you may be able to reason your way away some of the pathological tendencies that come with that Compassion. Being especially high in Big 5 Openness may also mitigate those tendencies.
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BTW, two subtraits for each of the Big 5 have started to emerge from factor analysis.