Why was James Madison against the great compromise?

James Madison opposed the Great Compromise because he believed it undermined the principles of the Virginia Plan, which favored representation based on population. He thought that equal representation for states in the Senate would disproportionately empower smaller states and dilute the influence of larger, more populous ones. Madison feared this would hinder effective governance and compromise the ability of the federal government to address the needs of the majority. Ultimately, his concerns reflected a desire for a stronger national government that could better serve the interests of the entire nation.