Hal Lindsey Needs to Thank the Old School Unitarians and Universalists

They were apocalyptic. They were also the first who believed history would terminate in universal liberal democracy (i.e., "millennial republicanism").

From the above link:

The late eighteenth century was another age of widespread apocalyptic expectation, when the promise of the American Revolution, followed by the greater and more radical expectations raised by the early years of the French Revolution, revived among a number of English Nonconforming sects the millenarian excitement of Milton and other seventeenth-century predecessors. "Hey for the New Jerusalem! The millennium!" Thomas Holcroft exulted in 1791. [] Preachers such as Richard Price, Joseph Fawcett, and Elhanan Winchester, as well as Joseph Priestley, who was not only a great chemist but a founder of the Unitarian Society, all interpreted the convulsions in France in terms of the prophecies in both the Hebrew and the Christian Scriptures. They thus invested the political events of the day with the explosive power of the great Western myth of apocalypse and expanded a local phenomenon into the expectation that humanity, everywhere, was at the threshold of an earthly paradise.

Price, Fawcett, Winchester and Priestley were all theological unitarians and/or universalists.