Upon the death of President William Henry Harrisonthirty days into his term Vice President John Tyler took office, with constitutional uncertainty, and would serve for the remaining four years of Harrison's term. Despite the fact that Harrison and Tyler were both members of the Whig Party, Tyler found much of the Whig platform unconstitutional, and he vetoed several bills favored by party leader Henry Clay. In 1841 Tyler was forced out of the Whig party after continued contention with Whig leaders. One year later the Whig party was routed in 1842 House elections where the party lost sixty nine seats and by 1844 the Whigs would lose control of the Senate. After his expulsion from the Whig party Tyler attempted to return to the Democratic party, but the still pro-Van Buren party would not allow him to enter leading to Tyler's realization that the only way he could maintain his legacy was to come out and show public support for the annexation of Texas. On the same day as the Democratic Convention thousands of Tyler supporters marched to Baltimore, Maryland and held their own convention believing that the Democrats, who were deadlocked between Martin Van Buren and Lewis Cass, would choose Tyler as a compromise candidate to unite the party. However, the Democrats instead chose James K. Polk, the former Speaker of the House, as their candidate, much to the dismay of the Tylerites. The Tylerites would receive a morale boost after Tyler announced his candidacy for the presidency after receiving the nomination of the new Democratic-Republican party from the convention that was formed by his thousands of supporters.
Party platform
Despite the fact that Tyler was determined to win another term, his new party lacked both a party platform and a vice presidential candidate. The issue that held precedence for Tyler was the annexation of Texas which was made limp by Polk's announcement of his support in favor of annexation.
Merging
By late July and early August both Tyler and the Democrats had entered negotiations with the goals of preventing Tyler from spoiling the election and giving the presidency to Henry Clay and Tyler getting the Democrats to commit themselves to the annexation of Texas. Andrew Jackson sent word to Tyler saying that if the President withdrew from the race, that he would at least have the pleasure of taking Clay down with him. With assurances that his followers would be welcomed into the Democratic ranks, Tyler announced the end of his candidacy on August 20 and threw his meager support to Polk. Polk would narrowly defeat Clay in the election and would follow through on Tyler's late order to annex Texas, eventually culminating in the Mexican–American War.
