Answer:
Formation of the Republican party.
Explanation:
Senator S.A. Douglas proposed a certain organization of Kansas and nebraska. This angered many people because it weakened Democrats, who at the time were slave-owning southerners. Polarization caused the Former Federalist Whig Party to join forces with anti-slavery freesoilers, forming the Republican party.
It's not the Fugitive Slave act because that had already been enacted 4 years prior (Compromise of 1850).
Popular sovereignty was not eliminated. It became a dividing factor in tensions leading up to the Civil War.
The enforcement of the Missouri Compromise had already been broken when Kansas was granted popular sovereignty.
