As I understand it, 'critique', in the political not the epistemological sense of the term, begins with the critique of religion at the beginning of the 19th Century.
As we know, with the 'end of ideology' in the mid 1950s, critical thinking 'turned to language' and became a 'discursive endeavour'. As such, 'critique' became increasingly understood as the micro-critique of power through the careful analysis of the operation of language/representation in local settings.
Of course many found this idea of critique profoundly unsatisfying - largely because it seemed to imply an anti-realist rejection of the 'real material world'. It also opened the way for a relegitimation of the religious/spiritual as a mode of critique.
The question is where we can locate the resources for a serious, systematic and significant mode of critique today. Some have looked to the Deleuzian moment in contemporary philosophy and argued that it represents an attempt to rehabilitate a realist/materialist approach to philosophy. The Bergsonian aspects of Deleuzian thinking are more intriguing and maybe a vitalist conception of matter that collapses the distincttion between matter and form does offer some critical purchase.
However - its Reichian/Laingian roots notwithstanding - the critical dimensions of this aspect of Deleuzian thinking are not that easily discernible. What is the point of being a materialist without any sense of the historical? Where does history play itself out in Deleuze's flat process ontology? Might Deleuze, in just this way, be the quintessential neo-liberal philosopher?
The idea of critique that we seem to be left with is the idea of 'spiritually informed' critique of the present and, as such, the beginning of critique today must be a crituque of science as the great disenchanter. I think that this is where critique starts today, with the critique of science - and we are quite a long way from the 19th century here I think...