Why were southerners against banning slavery in Missouri?

Southerners opposed banning slavery in Missouri because they viewed it as a threat to their economic interests and way of life, as the agricultural economy in the South heavily relied on slave labor. Additionally, they feared that restricting slavery in Missouri would set a precedent for other territories and states, potentially leading to the gradual abolition of slavery across the nation. The debate over slavery was also deeply intertwined with issues of states' rights and political power, as southern states sought to maintain their influence in Congress.