Why did most southern political leaders praised the Supreme Court decision in Dred Scott v. Sanford 1957?

Most Southern political leaders praised the Supreme Court decision in Dred Scott v. Sanford (1857) because it reinforced the institution of slavery and denied the citizenship rights of African Americans. The ruling declared that Congress had no authority to prohibit slavery in the territories, effectively allowing slaveholders to expand slavery into new areas. This decision aligned with Southern interests and bolstered their political power, contributing to the protection of slavery as a central aspect of their economy and social order.