Even though Harrison managed to beat Van Buren in a impressive election last time, he died shortly after taking office. His vice president John Tyler became president after that. Except he wasn't very popular and dropped out of the general election.
Democrats then threw their support to James K. Polk, the former Governor of Tennessee.
Martin Van Buren tried to get the Democratic nomination, but failed in the long-run to Polk. Though pretty rare for a former president to seek a nomination after losing.
Senator Henry Clay once again tried to become president by becoming the Whig candidate. The main issue of the campaign was the issue of Western expansion and the annexation of Texas. Which Polk supported, and Clay had a weak stance on.
Despite a rather odd primary, the general election was rather bland and unbiased in comparison to recent elections. Therefore it was rather half and half. The popular vote was close between Polk, and Clay, however Polk had the obvious edge in the electoral vote. Polk beat Clay 170-105.