"The legislative package known as the Compromise of 1850 postponed the Civil War by a decade.

Question

However, like the 1820 Missouri Compromise, the Compromise of 1850 failed to resolve the question
of slavery in a meaningful way. Over the course of the 1850s, the inadequacies of both measures
were made painfully clear. 'Popular sovereignty' undermined the Missouri Compromise by suggesting
the earlier division of the country along the thirty-sixth parallel into free states and slave states no
longer applied. Indeed, the Kansas-Nebraska Act of 1854 permitted slavery. The resulting bloodshed
in Kansas, like later incidents at Harpers Ferry, presaged the violent conflict of the Civil War."
- Daniel Webster, Seventh of March speech
Use the passage to answer the quesiton.
What is meant by "popular sovereignty undermining the Missouri Compromise?"
(2 points)
It means that it upheld the efforts of the compromise to maintain an equal balance of free and slave
states.
It means that it forced enslaved people who had escapted to be returned to a slave state.
It means that it expanded slavery to the northern free states.
It means that it reopened the debate over the border between free and slave states.

Answer 1

The correct answer is: It means that it reopened the debate over the border between free and slave states.

This reflects the idea that "popular sovereignty" allowed new territories to decide for themselves whether to permit slavery, which challenged the established boundaries set by the Missouri Compromise.