What did the 1856 election reveal about the democrats and the republicans?

Slavery was the major issue in the 1856 election. Democratic Party candidate James Buchanan endorsed popular sovereignty giving the power to determine the legality of slavery to the inhabitants of the territory seeking statehood, rather than to Congress. The Republican Party opposed the extension of slavery into the territories. Buchanan warned that if the Republicans won the election, their anti-slavery position would lead to civil war.