Answer:
South Carolina's leaders supported the commerce compromise because it allowed the state to exercise slavery for the next 20 years with no tax on the exported goods.
Step-by-step explanation:
South Carolina leaders support the Commerce Compromise because it supported exports not to be taxed. Another compromise resulted in slavery which allowed South Carolina to regulate the slave trade and system for the next 20 years without and restriction from the government. The Commerce compromise became introduced after drafting of the United States Constitution in 1787.