Yancey recognized the significance of the Wilmot Proviso to the South and in 1847, as the first talk of slaveholder Zachary Taylor as a presidential candidate surfaced, Yancey saw him as a possibility for bringing together a Southern political movement that would cross party lines. Yancey made it clear that his support for Taylor was conditional upon Taylor denouncing the Wilmot Proviso. However, Taylor announced that he would seek the Whig nomination, and in December 1847 Lewis Cass of Michigan, the leading Democratic candidate, endorsed the policy of popular sovereignty.