Whigs and democrats embraced the idea of popular sovereignty.
Step-by-step explanation:
Whigs party is founded by Henry clay that was against slavery. They supported the second bank of United States formation which was deplored by Andrew Jackson. They were not anti-slavery party but they were abolitionists.
This act proposed popular dominion and left the choice of the formation of free or slave state in the hands of the people. It also was against the Missouri compromise. Whigs were alarmed and the party faced downfall only to be formed again as a republican party which was founded by Abraham Lincoln.