Here is another perspective on the social justice/equal opportunity issue. It is not the premise of social justice that *all* students have the same potential - it is that the *distribution* of potential is the same among different subgroups of the population. Take, for example, socioeconomic status as a variable. If you take two kids with very high academic potential, one from a well-off family and one from a homeless family, in most school systems the kid from the well-off family is far more likely to get gifted services for several reasons. Suppose then, the well-off kid is selected for services because of a parent request while the low-income kid does not. If this happens early on in schooling, consider the following two implications. In the TAG program, the identified and well-off kid learns critical skills by tackling true academic challenges and learns to self-identify as "smart," while the kid from the low-income family does neither. There is a feedback here for both kids that will amplify over time and will be hard to reverse later on. In our district, economic disparities fall for the most part along racial lines, so it is perceived as a racial issue as well. The differences may also be amplified by racial stereotypes held by the teachers the students encounter.
It is not clear that there is much possibility to change people's minds about this, as proposed above, or even that it is desirable. I have grown to have a lot of admiration for those I know in the school system who take the social justice perspective. They would agree with you that in a classroom of kids, each one has different learning needs that should be addressed, but they are working very hard to develop models to address those needs in an equitable way, a way that does not exacerbate the disadvantages an otherwise smart kid has no control over. They are by no means of a "no child gets ahead" mentality, but are in the trenches tackling multiple facets of a complex issue.
