The Romantic movement began in a period of revolution and ended in a period of reaction. Many of the English Romantic poets embraced the ideals of liberty, fraternity, and equality that characterized the early vision of the French Revolution as the start of a new and better age for humankind. Many of them embraced the republicanism of the new United States. Republicanism, which does not refer to a political party but to the idea of a government headed by an elected official, not a hereditary monarch, was a radical idea at the time.
Some of the Romantics, such as Wordsworth, became deeply disillusioned with the French Revolution. Wordsworth happened to be in France when the revolution turned into a bloodbath, and he returned to England depressed and unhappy. He turned away in despair from the idea of politics as the way to liberate the common man and refashioned himself as a poet-prophet who wrote about common people in a way that idealized them and made them appealing to the upper classes, a very Romantic pursuit.
When the Napoleonic Wars started, England had a strong reaction against radicalism. The government feared English radicals would work with the French to enable a French invasion of England. This led to a conservative backlash. Wealthier Romantics like Shelley and Lord Byron sallied forth to the environs of places like Switzerland and Italy. Coleridge and Southey dreamed of establishing a utopian society in Pennsylvania. Charles Lamb and others moderated their public pronouncements of radicalism. By the end of the Romantic period, many of the poets, such as Wordsworth or Coleridge, who had not died young genuinely turned to conservatism.