Ideology in Marxist thought (dialectical materialism) is a set of propositions elaborated, in bourgeois society, with the purpose of making the interests of the dominant class appear with the collective interest, building a hegemony of that class.
The left is characterized by the defense of greater social equality.
Concern for citizens who are considered to be at a disadvantage compared to others and an assumption that there are unjustified inequalities that must be reduced or abolished.