After all, it was precisely at this moment that the museum was beginning its transition from a site within the bourgeois public sphere where democratically formed subjects would encounter experience of the unconscious, to an institutional rallying point where all the forces of contestation and subversion, initially operative in the artistic practices of the avant-garde and the neo-avant-garde, could now be condensed and controlled under the mythical auspices of universal democratic accessibility in the enforced practices of consumption

Think it’s a rather ‘end of career’ cynical commentary that our museums etc. are nothing but extensions of 21st century rampant consumerism / that the 60’s have been and gone (and v. few people read Art Monthly any more) / that we all need to read David Marquand’s new book: 'Mammon’s Kingdom' ...

As far as I can tell (which isn't very far), I think Prof. Buchloh is saying "buy this picture".

I don't think it means anything. Difficult text is often difficult because the underlying ideas are hard and take some work to understand (Hegel). Or sometimes it's badly written but intelligible if you make the effort to untangle it (e.g. Roy Bhaskar). I think Buchloh is padding his text with literal nonsense. The give away for me was the term 'democratically formed subjects'. In that context he can't mean 'subject' in the sense of subordinate ('the Queen's subjects'), but rather subject as in 'active agent'. But 'subjects' are logically prior to democracy, not formed by democracy. You can of course make an argument that it's a dialectical process, but I don't see what relevance that would have for a catalogue entry on Richard Hamilton, or why it matters for that sentence. There seem to be lots of redundancies in the sentence, but that's an example of a redundancy that doesn't even make sense. 

 I think he's trying to say something like "At this time museums were changing from public spaces where people could be awed by art to more critical spaces that reflected the radicalism of avant garde art. But under the rubric of democracy and access, that radicalism was rather blunted by a consumerist ethos". Put that way, it raises lots of questions that are avoided by added verbiage (why does he need to qualify 'public sphere' as 'bourgois', for example?). But I can only guess at what he might mean. 

It's a nice balance to Alain de Botton - both writing drivel, one over-simplifying, one over-complicating, neither elucidating anything.

Buchloh clearly has picked up a set of cubes with art pseudo jargon (the sort reserved for petit bourgeois sushi parties) and let the roll of these dice assemble what you generously call a sentence.  As for meaning, that too is clear - Obfuscation can be a substitute for scholarship - at least at Harvard.  I prefer New Haven...

In the immortal words of the Swedish Chef from The Muppet Show: 'Bok, bok, bok...'