A back issue of an old magazine lends support to the notion that artists tend to be socialists by nature:

THOSE familiar with art circles in England and on the Continent are aware that in those circles, and to some extent in those of America, are to be found a large number of men in sympathy with Socialistic principles. (“Why Artists Are Socialists,” The Literary Digest, February 3, 1900)

John Ruskin - A self-proclaimed "communist"

Two names from those “circles” should be familiar to some: John Ruskin and William Morris.

No surprise that utopian impulses played (and still play) a part:

A New York artist, Mr. F. W. Coburn, states briefly a few reasons why the artistic temperament, as notably in the case of William Morris, naturally turns to an ideal of society that promises to do away with the unequal and squalid conditions which characterize much of the life of to-day. (Ibid.)

In addition, who paid the bills mattered a lot:

In the first place [asserts Mr. Coburn] most artists would rather work for the state than for private individuals. They don’t like to be upper servants of the rich. The position of a painter or a sculptor dependent upon the whims of some crusty old capitalist is not dignified. The man who does large work for the Government knows that it will be seen by everybody; the painter of small easel pictures is aware that what he does will be incarcerated in some aristocrat’s private gallery. Public art is the art we need. (Ibid.)

Oooh, those mean ol’ capitalists:

Then, too, the artists do not like the looks of the world for which the present industrial system is responsible. It is nasty to look at—filled with cheap, tawdry display and ugly squalor. The artists believe that cooperation in industry will make clean cities and beautiful rural districts. They hold that ugliness is no necessary part of civilization. Not only is the external mold of to-day an eyesore; the lives of men have become stale and flat. Work used to be a privilege as well as an obligation; today the artists are almost the only class of hand-workers who can thoroughly enjoy their craft. The artists believe that Socialism will restore to all men the right to an interesting occupation. Under Socialism men will be able to pay more attention to the fine arts than they now can give. Cooperation will mean increased individual productiveness and greater industrial freedom from excess of labor. What the artist does will be better understood and appreciated under Socialism. (Ibid.)

Thus, “. . . under Socialism,” says Mr. Coburn, everybody’s cultural understanding and appreciation for art will—naturally, of course, it goes without saying—rise to unprecedented heights:

William Morris

Finally the artists feel that the coming age will be less cynical and ignoble than the present age. They are for the most part a sincere body of men; they take their art seriously. What they lack, however, is the inspiration of high national and social ideals. When an enthusiasm for mutual helpfulness shall have been established, when the industry of the world shall have been organized upon a basis of honor rather than dishonor, when the nobility of the many shall have asserted itself against the meanness of the few—then we shall have a great inspired art . . . . (Ibid.)

The full article is here.