When a government imposes a fine to coerce citizens to follow a law, which technique of enacting domestic policy is it employing?

Authoritative

Explanation:

Public policies are sets of programs, actions and decisions made by governments with the direct or indirect participation of public or private entities that aim to ensure a certain right of citizenship for various groups of society or for a particular social, cultural, ethnic or economic segment. That is, they correspond to rights guaranteed in the Constitution.

When the government determines a public policy in the form of law and imposes a fine to force citizens to comply with the law, the government is employing authoritative technique to enact the domestic policy that has been established.

They differed in the decision whether slavery would continue to exist in the South.

Lincoln used to express moral opposition to slavery in public and in private. He attempted to stop the expansion of slavery and proposed compensated emancipation at the beginning of his presidency. Later, he stated that slavery should not be allowed to expand any more U.S. territories. He was afraid of the expansion blocking "free labor on free soil" in new western lands.