The 1844 Democratic presidential candidate, James K. Polk, became a big promoter of Manifest Destiny as he ran on a platform of taking control over the entire Oregon Territory, as well as Texas and California. He used the famous campaign slogan "Fifty-Four Forty or Fight!"—named after the line of latitude serving as the territory's northern boundary. Polk's plan was to claim the entire region and go to war over it with the British. The United States had fought them twice before in relatively recent memory. Polk declared that the joint occupation with the British would end in one year.
In a surprise upset, Polk won the election with an electoral vote of 170 vs. 105 for Henry Clay. The popular vote was Polk, 1,337,243, to Clay's 1,299,068.