Congress has not declared war on anyone since 1941 but that never stopped the executive branch (now headed by the man you want to empower, Obama) from attacking individual liberty and shredding legal rights.
Re-read your Constitution. In a declaration of belligerency, it does not require Congress to use the precise words: "Declaration of War".
Both the Iraq War Resolution and the Authorization For The Use of Military Force (War on Terror) are declarations of war in their effect -- whether you personally agree with them or not.