The 1844 Democratic National Convention was held in Baltimore. At first, the Democrats were split between three candidates: abolitionist Martin Van Buren, former President of the United States and leader of the dominant Jacksonian faction; James Buchanan, Senator from Pennsylvania, a so-called "moderate"; and Ambassador to France Lewis Cass, a retired general and advocate of territorial expansionism.
The annexation of Texas was the chief political issue of the day. Van Buren, initially the leading candidate, opposed immediate annexation because it might lead to a sectional crisis over the status of slavery in the West. This position cost Van Buren the support of southern and expansionist Democrats; as a result, he failed to win the nomination. The delegates likewise could not settle on Cass, whose credentials also included past service as a U.S. minister to France.
On the eighth ballot, the historian George Bancroft, a delegate from Massachusetts, proposed former House Speaker James K. Polk as a compromise candidate. Polk argued that Texas and Oregon had always belonged to the United States by right. He called for "the immediate reannexation of Texas" and for the "reoccupation" of the disputed Oregon territory.
On the next roll call, the convention unanimously accepted Polk, who became the first dark horse, or little-known, presidential candidate. The delegates selected Senator Silas Wright of New York for Vice President, but Wright, an admirer of Van Buren, declined the nomination, becoming the first person to decline a vice presidential nomination. The Democrats then nominated George M. Dallas, a Pennsylvania lawyer.
In 1840, the Democratic Party Convention had provided that a majority vote would be sufficient for nominee selection. Northern Democrat Van Burenites arrived at the convention on May 27, 1844, with the expectation that, possessing a majority of the delegates, they would quickly secure the candidacy for their man. Early in proceedings, Senator Robert J. Walker of Mississippi, in cooperation with Senator James Buchanan of Pennsylvania, called for the reinstatement of the traditional 1832 and 1834 convention rule requiring a two-thirds vote for nomination (the rule would remain in place until it was revoked by Franklin Delano Roosevelt in 1936). Following a historical pattern in which a minority faction of Northern Democrats delivered votes to produce southern wing victories for pro-slavery legislation, the Van Burenite delegates split over the pivotal vote. Fully one-third of the pro-Van Buren delegates (52 of 154) voted to reinstate the two-thirds rule, along with 90 of 104 anti-Van Buren delegates, producing a final vote of 148 to 116. Van Buren supporters persisted in spite of this setback, garnering 146 votes for their candidate on the first ballot, a 55% simple majority, but short of the now required 177 votes. Middle and Deep South pro-annexationists opposed Van Buren 75 to 3, depriving northern anti-annexationists the 31 votes needed for victory.
Support for Van Buren dwindled in subsequent ballots from 146 to 99, at which point Van Burenites were reduced to blocking nominations of numerous candidates, among them James Buchanan, Lewis Cass of Michigan, John C. Calhoun and Levi Woodbury of New Hampshire. President John Tyler also hoped to win the support of delegates, but he was unable to find any backers. Southern intransigence had succeeded in eliminating Van Buren and his principled stand on Texas annexation. If the Democratic Party was to avoid dissolution at a national level, an acceptable nominee, fully committed to immediate annexation would be required, yet capable of unifying the party in the general election. Van Buren was open to deferring to Senator Silas Wright of New York, but Wright was uninterested in the position.
James K. Polk, a former Speaker of the House and Governor of Tennessee, had entered the convention in hopes of becoming the vice presidential nominee. For president, Polk had the backing of former President Andrew Jackson, who remained popular in the party. On the eighth presidential ballot, Polk was offered to the convention as an acceptable alternative for all Democratic factions at odds over the Texas annexation crisis. Despite Polk's fervent advocacy for annexation, he had remained loyal to Van Buren throughout the Texas controversy, and anti-annexationist Van Burenites were willing to accept Polk, with reservations, having already recognized him as a suitable vice-presidential choice to have complimented a Van Buren ticket. Southern Democrats benefited from the Tyler-Calhoun machinations in eliminating Martin Van Buren as a presidential candidate, and clearing the way for the pro-annexation nationalist Polk. On the ninth ballot, Van Buren instructed his delegates to support Polk, beginning a stampede to Polk that ended with him winning the nomination unanimously.
Despite Whig efforts to cast Polk as an unknown – "Who is James K. Polk" they asked rhetorically – he was respected as an effective political operator. His sobriquet "The Young Hickory" contained a dual reference, one to his mentor Andrew "Old Hickory" Jackson, and one to the term Young America, a reference to an international movements struggling to establish republican forms of government and the overthrow of monarchies and ascribed to Manifest Destiny Democrats.
James K. Polk, a slaveholder, never enunciated a slavery expansionist position with respect to Texas annexation, as had John C. Calhoun and the southern extremists. As a national imperialist, he exhibited an unwavering support for Manifest Destiny, perceived as a non-sectional devotion to expansionism, whether slave-soil Texas or free-soil Oregon Territory. Polk's political reputation was expected to diffuse northern Democratic resentment towards the Slavepower, while delivering Texas to the Deep South. On May 29, 1844, Polk was confirmed unanimously on the ninth ballot as the Democratic Party presidential nominee. Van Buren complied with his party's decision to unite under a pro-annexation candidate, and worked to win New York state for Polk.
Polk and Richard Mentor Johnson had both campaigned for the vice presidency prior to the convention, but with Polk's nomination, the party looked elsewhere for a running mate. The anti-annexationist Silas Wright, US Senator from New York, was offered the nomination for Polk's vice-presidential running mate. Wright declined on principle, and the convention settled on George M. Dallas, a conservative from Pennsylvania.
The basic events of the convention are outlined in the song James K. Polk by the rock band They Might Be Giants