1844: Calhoun (D) vs. Clay (W)

[The Undefeatable Debbie Stabenow]

I would see a narrow Clay victory. Clay's anti-expansionism would still be a detractor across much of the electoral map, but Calhoun's extreme "Southern states' rights"ism (notably relating to the Nullification Crisis) would probably be enough of a turn-off in the northern states to flip a couple of them that Polk narrowly won, despite solidifying his southern support.

Henry Clay (W-KY) - 153 EV
John C. Calhoun (D-SC) - 122 EV