This blog has gotten a few hits recently from people looking for leftist critiques of identity politics. I suggest starting here:
While David Harvey doesn't have much to say on the topic in A Brief History of Neoliberalism, he does offer this:
Neoliberal rhetoric, with its foundational emphasis upon individual freedoms, has the power to split off libertarianism, identity politics, multi-culturalism, and eventually narcissistic consumerism from the social forces ranged in pursuit of social justice through the conquest of state power. It has long proved extremely difficult within the US left, for example, to forge the collective discipline required for political action to achieve social justice without offending the desire of political actors for individual freedom and for full recognition and expression of particular identities. Neoliberalism did not create these distinctions, but it could easily exploit, if not foment, them.And:
Civil rights were an issue, and questions of sexuality and of reproductive rights were very much in play. For almost everyone involved in the movement of '68, the intrusive state was the enemy and it had to be reformed. And on that, the neoliberals could easily agree. But capitalist corporations, business, and the market system were also seen as primary enemies requiring redress if not revolutionary transformation; hence the threat to capitalist class power. By capturing ideals of individual freedom and turning them against the interventionist and regulatory practices of the state, capitalist class interest could hope to protect and even restore their position. Neoliberalism was well suited to this ideological task. But it had to be backed up by a practical strategy that emphasized the liberty of consumer choice, not only with respect to particular products but also with respect to lifestyles, modes of expression, and a wide range of cultural practices. Neoliberalization required both politically and economically the construction of a neoliberal market-based populist culture of differentiated consumerism and individual libertarianism. As such it proved more than a little compatible with that cultural impulse called 'post-modernism' which had long been lurking in the wings but could now emerge full-blown as a both a cultural and an intellectual dominant. This was the challenge that corporations and class elites set out to finesse in the 1980s.