With Barnburner Democrats and Conscience Whigs making common cause with the Liberty Party in the new Free Soil Party, the election of 1848 became a three-way race. The Free Soilers, by insisting on speaking out firmly and often on slavery and damning Democrat and Whig alike as Slave Power lackeys, made the expansion of slavery the campaign’s central issue despite their objections.
Hopes to remain silent and leave slavery out of the national debate dashed, both parties responded by trying to be all things to all people. The Democrats told the North that popular sovereignty would best keep slavery out of the territories. They told the South that Cass pledged to veto any Wilmot Proviso bills and reminded the voters that their party had acquired the vast territory to which slavery could now expand via popular sovereignty. They circulated one campaign biography of Cass in the North and another in the South.
The Whigs played the same game. Taylor pledged to defer to Congress on slavery, whatever it passed. The antislavery Whigs that had not bolted the party, like William H. Seward and Abraham Lincoln, read into that promise tacit support for slavery restriction. In the South, Taylor stood the hero of Buena Vista, where he led less than five thousand to victory against a Mexican army of sixteen thousand. Taylor also owned around four hundred slaves (in 1860, only 0.02% of slaveholders owned 300 or more*) so surely he would be no foe to the peculiar institution.
Taylor the blank slate won with 47.3% of the popular vote and the electoral votes of eight of the fifteen slave states and seven of the fifteen slave states. Cass took 42.5% of the popular vote and the remainder of the states. Van Buren won no states, but his Democrats gave New York to Taylor even as his Whigs gave Ohio to Cass.
Van Buren did not expect to win. In fact, he expected to throw the election to Taylor. But the Free Soilers succeeded in making slavery the issue of the campaign. They also took over from the Democrats as the opposition party in Van Buren’s three best states: Massachusetts (28.4%), New York (26.4%), and Vermont (28.9%). On the national state, the Free Soilers elected two senators, one being Salmon P. Chase who had helped arrange the merging of Barnburners and Conscience Whigs with the Liberty Party and wrote the Free Soil platform. They also collected nine House seats, largely from former Whig districts.
The Free Soilers did not shatter the two-party system, but they dealt it a serious blow and highlighted the sectional polarization that both major parties tried to avoid. After Taylor’s inauguration in March, the nation would learn if it had elected the war hero from the Louisiana planter class or the war hero that would sign any law on slavery in the territories that Congress sent his way.
*This figure can only be approximate. I plan a future By the Numbers post discussing how many slaves planters owned and the difficulties in doing so from census aggregates. But in any case, four hundred was a lot of people even by late antebellum Deep South standards.