James K. Polk runs for reelection in 1848

[Sir Mohamed]

What if James Knox Polk had stayed in the race and sought a second term in office? Is he reelected?

I suppose Zac Taylor would not run against his commander-in-chief during the Mexican war in such a scenario.

[🐒Gods of Prosperity🔱🐲💸]

Taylor may still have run with Polk seeking reelection - the Whigs surely would have done everything they could to convince him to run.

The Democrats renominate Polk, but replace Dallas (who has become controversial in his home state due to his role in passing the Walker Tariff) with fellow Pennsylvanian Sen. Daniel Sturgeon.  Polk is more well known and popular than Cass, and is slightly more amenable to free soil Democrats than Cass due to his support of extending the Missouri Compromise line to the Pacific - as opposed to Cass's popular sovereignty doctrine potentially extending slavery into Northern territories.

Polk / Sturgeon    45.9  179
Taylor/ Fillmore    44.8  111
Van Buren/ Adams  9.2

Polk wins reelection. When he dies during his term, Sturgeon is left as president.