Does W. B. Yeats' poetry change through his political views?
Yes and no. Yeats has three different locations around which politics operate differently, so he doesn't change along a time line really. There is rural Ireland (like in " The Swans at Coole" ) where he tries to avoid the political, but doesn't succeed--after all the very freedoms in the idyllic natural settings is at stake in the political battles of the times. Then, secondly, there is the urban in Dublin (as in "Easter 1916") where at times he is dealing directly with political violence as he and his countrymen try to overthrow the English occupancy of Ireland. Third, though, there is Yeats on the political global scale where he also operated. He was in some ways hopeful at the fin de siecle that change would be positive for Ireland and the world, while one must of course balance that Yeats knowledge of coming change with the apocalyptic nature of his view of time in the gyre (as in "The Second Coming"). Yeats wrote from all three of these variently political positions: the rural idealist, the Dublin Independent, and the global philosopher. His views did evolve over time, but the pressures of these varient locals provide, I think, a better logic for the political in Yeats' poetry. These disparate impulses are perhaps no where more balanced than in his transcendental wistfulness as he is trapped in the political turmoil of London and dreaming of the peaceful and free escape of natural beauty found in "The Lake Isle of Innisfree."