[214] Like Tyler, Calhoun pursued the annexation of Texas to upend the presidential race and to extend slavery into new territories.[215]
Shortly after taking office, Calhoun negotiated an annexation treaty between the United States and Texas.[216] Van Buren had hoped he would not have to take a public stand on annexation, but as the Texas question came to dominate U.S. politics, he decided to make his views on the issue public.[217] Though he believed that his public acceptance of annexation would likely help him win the 1844 Democratic nomination, Van Buren thought that annexation would inevitably lead to an unjust war with Mexico.[218] In a public letter published shortly after Henry Clay also announced his opposition to the annexation treaty, Van Buren articulated his views on the Texas question.[219]
Van Buren's opposition to immediate annexation cost him the support of many pro-slavery Democrats.[220] In the weeks before the 1844 Democratic National Convention, Van Buren's supporters anticipated that he would win a majority of the delegates on the first presidential ballot, but would not be able to win the support of the required two-thirds of delegates.