Even Clay, who had been against annexing Texas, had to twist his toe in the dirt, and say, alright, maybe we could annex Texas so long as it didn’t mean a war or cost too much.
Polk’s platform of territorial expansion would come to be known as Manifest Destiny. The “Destiny” part meant that United States was destined to keep on taking land until it reached the Pacific Ocean. The “Manifest” part meant, “Just watch us do it.”
That we were destined to take all the land occupied only by the Indians and Spanish (and some French) is incontrovertible by the fact we did do it, so Manifest Destiny turns out to have been a pretty sound theory after all. It operates on the same principle as if I’m sitting next to a big ol’ slice of strawberry cheesecake, and no one’s there to stop me, it’s Manifest Destiny sooner or later I’m going to eat it.
One other candidate (not pictured) was Joseph Smith, founder of the Mormon Church. Smith’s campaign was somewhat hampered by being in jail at the time; that and the fact he was assassinated before the election, effectively prevented his candidacy from getting off the ground. In the end, although the popular vote was a lot closer than the electoral, the former dark horse James Polk easily crossed the finish line first in electoral votes.
James K Polk: 170
Henry Clay: 105