Given the historical context, and Shelley's political views, what is the significance of his "Ode to the West Wind"?

The speaker invokes the "wild West Wind" of autumn, which scatters the dead leaves and spreads seeds so that they may be nurtured by the spring, and asks that the wind, a "destroyer and preserver," hear him. The speaker calls the wind the "dirge / Of the dying year," and describes how it stirs up violent storms, and again implores it to hear him. The speaker says that the wind stirs the Mediterranean from "his summer dreams," and cleaves the Atlantic into choppy chasms, making the "sapless foliage" of the ocean tremble, and asks for a third time that it hear him.

The speaker says that if he were a dead leaf that the wind could bear, or a cloud it could carry, or a wave it could push, or even if he were, as a boy, "the comrade" of the wind’s "wandering over heaven," then he would never have needed to pray to the wind and invoke its powers. He pleads with the wind to lift him "as a wave, a leaf, a cloud!"-for though he is like the wind at heart, untamable and proud-he is now chained and bowed with the weight of his hours upon the earth.

The speaker asks the wind to "make me thy lyre," to be his own Spirit, and to drive his thoughts across the universe, "like withered leaves, to quicken a new birth." He asks the wind, by the incantation of this verse, to scatter his words among mankind, to be the "trumpet of a prophecy." Speaking both in regard to the season and in regard to the effect upon mankind that he hopes his words to have, the speaker asks: "If winter comes, can spring be far behind?"

Each of the seven parts of "Ode to the West Wind" contains five stanzas-four three-line stanzas and a two-line couplet, all metered in iambic pentameter. The rhyme scheme in each part follows a pattern known as terza rima, the three-line rhyme scheme employed by Dante in his Divine Comedy. In the three-line terza rima stanza, the first and third lines rhyme, and the middle line does not; then the end sound of that middle line is employed as the rhyme for the first and third lines in the next stanza. The final couplet rhymes with the middle line of the last three-line stanza. Thus each of the seven parts of "Ode to the West Wind" follows this scheme: ABA BCB CDC DED EE.