<P> O'Sullivan's original conception of manifest destiny was not a call for territorial expansion by force . He believed that the expansion of the United States would happen without the direction of the U.S. government or the involvement of the military . After Americans immigrated to new regions, they would set up new democratic governments, and then seek admission to the United States, as Texas had done . In 1845, O'Sullivan predicted that California would follow this pattern next, and that Canada would eventually request annexation as well . He disapproved of the Mexican--American War in 1846, although he came to believe that the outcome would be beneficial to both countries . </P> <P> Ironically, O'Sullivan's term became popular only after it was criticized by Whig opponents of the Polk administration . Whigs denounced manifest destiny, arguing, "that the designers and supporters of schemes of conquest, to be carried on by this government, are engaged in treason to our Constitution and Declaration of Rights, giving aid and comfort to the enemies of republicanism, in that they are advocating and preaching the doctrine of the right of conquest". On January 3, 1846, Representative Robert Winthrop ridiculed the concept in Congress, saying "I suppose the right of a manifest destiny to spread will not be admitted to exist in any nation except the universal Yankee nation". Winthrop was the first in a long line of critics who suggested that advocates of manifest destiny were citing "Divine Providence" for justification of actions that were motivated by chauvinism and self - interest . Despite this criticism, expansionists embraced the phrase, which caught on so quickly that its origin was soon forgotten . </P> <P> Historian William E. Weeks has noted that three key themes were usually touched upon by advocates of manifest destiny: </P> <Ul> <Li> the virtue of the American people and their institutions; </Li> <Li> the mission to spread these institutions, thereby redeeming and remaking the world in the image of the United States; </Li> <Li> the destiny under God to do this work . </Li> </Ul>

How was the idea of manifest destiny brought about by nationalism