Whatever else one may say of modernism, it was not a simple phenomenon, and many of its leading practitioners, including T. S. Eliot, held conservative attitudes. One aspect of modernism was a reaction against the conventions of nineteenth-century Victorian and Romantic poetry, which often meant going both farther afield geographically and farther back in time. Eliot was far more influenced by Virgil and Dante than he was by Tennyson and Browning, and he could thus claim to be restoring what was classic in literature.
Modernist poets resisted the poetic conventions of Victorianism, experimenting with new forms of verse and hard-edged images. However, the newness of the style did not imply that they were celebrating modernity. Many of Eliot's poems, "The Waste Land" in particular, make it clear that Eliot dislikes the modern age, viewing it as dull, tawdry, and vulgar. However, the solution he finds (insofar as he finds one at all) is not to retreat into nostalgia for the nineteenth century, but to resist modernity in a new way, using the literary weapons provided for him by ancient cultures.
As John Carey points out in The Intellectuals and the Masses, one of the defining aspects of modernity is the idea of democracy, while the leading modernists were determinedly anti-democratic in their writing. The very obscurity and allusiveness of Eliot's famously "difficult" poetry is a form of opposition to this democratic spirit. Eliot shows his hostility to the common man by continually producing work that the common man cannot understand, addressing himself to those who, like him, are steeped in the classical tradition.