As far as art and politics is concerned, one must take into account the role of artists in society in general.
Ancient art like in India, China, Greece, Middle and South America, served a religious role from the beginning (you can trace this back to the Cro-Magnon caves with their wall paintings and statuettes) that had a strong connection with political power - in fact, religious and political power were essentially the same at that time (an ideal dictatorships still are keeping).
Not much later, let's say in the Bronze Age for example, there also came the need for representative and decorative art in the palaces. The legend of King Minos is stating that he employed Daidalos and his son Ikaros as court artists and inventors at his palace at Knossos.
The Romans made extensive use of imperial architecture and statues to celebrate the power of their rulers and impress the ordinary people, a tendency that also persists until today.
So, the basic connection between art and politics is an essential one within any human society, always in use by those in power. In this context, propaganda seems just an extreme form of public regime representation with strong pseudo-religious connotations in dictatorships - but certainly not only in dictatorships.
You can feel this with Hitler and Albert Speer - but when the new government buildings were erected in Berlin in the past decade, decisions had to be made about styles, architecture, and representative art as well, as they had to be made for the construction of Brazilia, the new capital by Costa and Niemeyer, and likewise for any capital in the world.
The left-wing artist seems to me a phenomenon with its roots in Italian renaissance. You need an advanced civil society first, to make at least some artists independent of pure government orders, that is, to enable them of working on a free basis, together with new ideas of humanity, a thread that can be followed over the age of enlightenment to the revolutions of the 18th to the 20th century - so finally the working masses would be having their art, too, as it was strongly pushed by the followers of Karl Marx that there had to be a connection between the working class and the intelligentsia.
That tendency of democratizing art was well underway when photography came up in 1839. The invention and patents of the process were even sold to the French State right in the beginning.
If you take these clues together, you have it all: the government interests, the propaganda, the conservative and the progressive tendencies.
It is this field of tension in which photography is constantly standing.
Jesko
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2006 AD
800 yrs Dresden
80 yrs Zeiss Ikon