How better to celebrate my dear wife's birthday than with a dirty weekend in Margate (with her)?

Never been to the town before. The main purpose was to see the Turner Contemporary gallery. (This was in advance of viewing Mike Leigh's magnificent Mr Turner - highly recommended. Though the "Margate" scenes were filmed in Cornwall because it doesn't actually look like that any more.)

Margate is well weird. The hotel we were booked into ... let's say it may be the subject of a surrealist novel I plan to write one day. Good breakfast in a large, mouldering ballroom, where the few other guests appeared to be DSS claimants - I heard one woman confide to the elderly lady who served us our meal that she'd "been in a fight last night" and had been "having seizures". A lot of grime and tat. A wonderful sunset over the harbour arm on the Saturday night, worthy of Mr Turner himself. And the rest of the Island of Thanet (which has not been an island for centuries) (whose name Richard Makin tells me is derived from the Greek thanatos, or death, though this apparently is disputed) was kind of interesting. We started off in lovely Deal, visiting John Tilbury, and also motored around Broadstairs, Ramsgate and Sandwich.

Back to the Turner Contemporary. It sits in a corner of the harbour (apparently on the very site of the boarding house JMW Turner lived in), a modernist building rather at odds with its surroundings. Big, clean spaces, characterless.

I didn't realise there was no permanent collection there. The main current exhibition, occupying the vast majority of the space, was "English Magic" by Jeremy Deller, a re-creation of his multi-room installation for the British Pavilion at the 2013 Venice Biennale.

The handout explains that "'English Magic' explores the diverse nature of British society - its people, icons, myths, folklore and its cultural, socio-political and economic history". Which sleight-of-hand is the kind of thing that understandably gets the Scots desperate for independence, but let's blame the blurb writer rather than the artist.

Deller is basically a conceptual artist who brings together various media - mural painting, fabric, objects, photographs and film - in the service of a complex of interwoven ideas about contemporary culture and politics. He doesn't appear to do much of the hands-on work himself.

Thus, the first of the seven galleries, "We sit starving amidst our gold", is dominated by a vast mural depicting an angry William Morris tossing Roman Abramovich's yacht into the sea, which it turns out is not painted by Deller at all but (the small print says) by Stuart Sam Hughes. It's not very good, in truth. Abramovich is no doubt a worthy symbol of the obscenity of uber-capitalism. The yacht (I once saw it moored off Gibraltar, though I was told Abramovich actually has two identical yachts so as to fox his enemies, which is even more obscene) is depicted as a crude waterline drawing.

Works by Turner, William Morris and John Ruskin, presumably representing a countervailing socialism, or at least public integrity, complete the contents of this room. Actually, I have never "got" Morris or his brand of socialism. Yes, there are examples of his hand-crafted wallpaper there, the irony of course being that it is only billionaires like Abramovich who could afford to have such non-mass-produced decoration on their walls. (Also, I can't help pointing out that Mike Leigh has Ruskin depicted in his film as an effete, lisping, if somewhat likeable, upper-class twit whose compliments and critic-speak Turner barely tolerates, but I guess that's just naughty.)

The second room houses the best bit of the exhibition, a film composed of a montage of images, including the London Lord Mayor's parade (armed forces marching, freemasons on a bus), a Range Rover being crushed in a scrapyard (the actual crushed vehicle has been fashioned into the bench on which you watch the film) and various raptors swooping in slow motion, all synched to incredibly mournful sounding steel band versions of Vaughan Williams' music and David Bowie's "The Man Who Sold the World".

Stunning as the raptor images are, we are confronted here with the major problem I have with this exhibition, and with much so-called "political" art in general. The birds' talons are over-obviously juxtaposed with the claws of the wrecking machine that is disposing of the Range Rover, and, in case you didn't get the message, in a further gallery there is another huge mural with, lo and behold, a hen harrier (the reference is to a bird allegedly shot by Prince Harry and a friend in Sandringham in 2007) with a Range Rover in its claws.

In other rooms, photographs of David Bowie's 1972-73 Ziggy Stardust tour of the UK are alternated with news pictures over the same period depicting industrial action, economic depression and IRA bombing incidents; there's an exhibition of drawings and paintings by UK prisoners ("many of whom are former soldiers who served in Iraq and Afghanistan" - how many, and in what precise way is this linked with the death of Dr David Kelly, documented here?); and a display of banners and another indifferent mural, depicting St Helier, the capital of Jersey in the Channel Islands, burning down after "the UK public descend on the town, angered by Jersey's status as a tax haven". This last puzzled me at first, because I couldn't remember this incident, until I noticed the dateline "12 June 2017". So it's a wish-fulfilment fantasy set in the future, though why the ordinary residents of St Helier, rather than the UK tax avoiders themselves, should be punished in this way is a troubling question.

I'm sorry, but I'm really rather embarrassed this lot represented Britain at the Venice Biennale last year. It's "engaged art" at its worst, the politics jejune, the iconography obvious to the point of banality. Roman Abramovich and his yacht, Range Rovers, the island of Jersey and its tax-avoidance industry, Prince Harry and the Iraq and Afghanistan wars are Bad. Morris, Ruskin, Turner, birds of prey (representing the natural world?), perhaps David Bowie, multi-cultural steel band orchestras (though we can't help noticing the one seen in the film appears to be directed by a white person, so a hint of ambiguity here) are Good. The claws of the wrecking machine are identified with the raptors' talons, so are they Good or are they part of the Bad capitalist machine? Another rare hint of ambivalence.

Does it undermine assumptions? Does it make you think? Does it transform your vision of the world?

Hmm.

Now I'm on a roll, I'll turn my attention next to the Chapman brothers at the Jerwood Gallery, just down the road from me.

"English Magic" is at the Turner Contemporary in Margate until January 2015