Democrats stood for the 'sovereignty of the people' as expressed in popular demonstrations, constitutional conventions, and majority rule as a general principle of governing, whereas Whigs advocated the rule of law, written and unchanging constitutions, and protections for minority interests against majority tyranny.
The Whig Party nominated several presidential candidates in 1836. General William Henry Harrison of Ohio was nominated in 1840, former Senator Henry Clay of Kentucky in 1844 and General Zachary Taylor of Louisiana in 1848. Another war hero, General Winfield Scott of New Jersey, was the Whig Party's last presidential nominee in 1852. In its two decades of existence, the Whig Party had two of its candidates, Harrison and Taylor, elected president and both died in office. John Tyler succeeded to the presidency after Harrison's death in 1841, but was expelled from the party later that year. Millard Fillmore, who became President after Taylor's death in 1850, was the last Whig President.
The party fell apart because of the internal tension over the expansion of slavery to the territories. With deep fissures in the party on this question, the anti-slavery faction prevented the nomination for a full term of its own incumbent President Fillmore in the 1852 presidential election—instead, the party nominated General Scott. Most Whig Party leaders eventually quit politics (as Abraham Lincoln did temporarily) or changed parties. The Northern voter base mostly gravitated to the new Republican Party. In the South, most joined the Know Nothing Party, which unsuccessfully ran Fillmore in the 1856 presidential election, by which time the Whig Party had become virtually defunct. Some former Whigs became Democrats. The Constitutional Union Party experienced significant success from conservative former Whigs in the Upper South during the 1860 presidential election. Whig ideology as a policy orientation persisted for decades and played a major role in shaping the modernizing policies of the state governments during Reconstruction.
The name "Whig" derived from a term that Patriots used to refer to themselves during the American Revolution. It indicated hostility to the British Sovereign and despite the identical name it did not directly derive from the British Whig Party (see etymology).
The American Whigs were modernizers who saw President Andrew Jackson as "a dangerous man on horseback" with a "reactionary opposition" to the forces of social, economic and moral modernization. The Democratic-Republicans who formed the Whig Party, led by Kentucky Senator Henry Clay, drew on a Jeffersonian tradition of compromise, balance in government and territorial expansion combined with national unity and support for a Federal transportation network and domestic manufacturing. Casting their enemy as "King Andrew", they sought to identify themselves as modern-day opponents of governmental overreaching.