Why were southern political opposed to the wilmot proviso?

Southern politicians opposed the Wilmot Proviso because it aimed to ban slavery in any territory acquired from Mexico, which they viewed as a direct threat to their economic interests and way of life. They believed that the expansion of slavery was essential for the agricultural economy of the South. Additionally, Southerners feared that the Proviso would upset the balance of power between free and slave states in Congress, jeopardizing their political influence. This opposition highlighted the growing sectional tensions that eventually contributed to the Civil War.