The last step is crucial, inasmuch as the people's jealousy for their liberty must be directed more against the legislature, the branch ostensibly closest to them, than against any other. In every form of government, the Federalist cautions, the most powerful branch is always the most dangerous to the people's freedom. In a monarchy, it is the executive that ought to be feared. But in a republic, it is the legislative. In the state governments, for example, with their weak executives, it is the legislative department that is "everywhere extending the sphere of its activity and drawing all power into its impetuous vortex." Therefore, Publius admonishes, "it is against the enterprising ambition of this department that the people ought to indulge all their jealousy and exhaust all their precautions." To protect their rights and liberties the people must insist on limited national government, but that means the people must limit Congress more effectually than they had the state legislatures; and the Federalist argues that the Constitution's improved separation of powers (along with bicameralism) will do just that. 
The separation of powers in Australia’s State constitutions is less clear than in the Commonwealth Constitution. According to Carney (1993), the Supreme Courts in New South Wales, South Australia and Western Australia have ruled that the doctrine of the separation of powers does not apply in the States. The State constitutions do not contain clear divisions of power. For example, they do not create supreme courts or vest them with judicial power. Despite this, State practice on the separation of powers essentially mirrors Commonwealth practice.
However, the problem is further complicated by the view that, in Book XI, Chapter 6, Montesquieu was creating an ideal type of a “constitution of liberty,” with England as its source, but that he was not describing the English Constitution as it actually existed. When Montesquieu wrote of “England” here he was writing of an imaginary country, as in the Lettres persanes: “ l’Angleterre de Montesquieu c’est l’Utopie, c’est un pays de rêve. ” 41 Thus in certain respects Montesquieu’s statements in this chapter differ considerably from what he actually knew to be the case in England. For example, he writes of the judiciary as if it contained no professional judges, as if juries were judges of both fact and law. The reality of English life was, as Montesquieu himself notes elsewhere, quite different from the ideal situation depicted in XI, 6. 42 If, therefore, this chapter also constructs an “ideal type,” we must consider it on its merits, and not concern ourselves with the long controversy over the correctness of Montesquieu’s description of the early-eighteenth-century constitution of England. 43 But how does this ideal type relate to his ideal types of monarchy, despotism, and republic? Is it a fourth and quite distinct category, or a sub-category of one of them? These questions are no doubt unanswerable, for they demand from Montesquieu a consistency he does not have. We must accept these inconsistencies, and make the best of them.