The rule of law ensures that leaders can only exercise the powers the people give them.
From the rule of law we arrive at the fundamental conception of modern constitutionalism, namely the prevalence of the principle of separation of powers. This is envisioned as an instrument, a guarantee, an essential technique for stopping the agency and whims of any government, whatever ideology it may be. The general rules must be impersonal, obligatorily applied equally, including to the political agents of the Executive and Legislative Powers when acting in defense of their private and private interests even if they are in the public interest and / or in defense of the common good.
