Low Toryism mixed with certain post-war/cold war economic/sociological/etc fads carried out by people who deluded themselves into believing that they were, in fact, liberals after all. There's been some great work on this subject over the past decade or so.
I have to stress Thatcher's neoliberalism, and neoliberalism in general,
are liberal ideologies. Liberalize the market, essentially. They come from the same ideological pool. Considering this, it's not nearly a stretch to see the Obama administration in the same light, albeit with a veneer of social consciousness, which is liberalism.
Modern corporatist liberalism, and it's offshoots are the extensions of the paradigm shift in the age of enlightenment applied to modern social conditions. All the good, the permissiveness, the subtle anti-binary thinking, the focus on welfare, plus all of it's evils.