A controversial question in critical discourse analysis has been whether and how discourse may manifest or at least implicate the ideologies of the discourse participants. This question should be seen in the context of the long history of uneasiness concerning whether ideology can be an object of inquiry for science, whose stance of authority and objectivity implies a claim to be freed of all ideology. This claim has been quite emphatic in formalist linguistics, which has even proposed to investigate human language in isolation from human society. By restoring the focus upon discourse in society, critical discourse analysis offers an occasion to subject ideology to new methods of investigation, and to formulate an explicit ideology for the field itself. As a new source of evidence, large corpus data can be collated for expressions which are presumed to undergo ideological contestation, such as 'liberal' and 'liberalism', which are examined here in data from the UK, the US, and South Africa.