The permanent bureaucracy makes the top of the list, probably because it’s both permanent and a bureaucracy. From Ryan McMaken at mises.org:
The US federal government is divided up into a variety of institutions, with the three main “branches” of government designed to compete against each other. Theoretically, these three branches were initially thought to place checks on the other branches of government, thus minimizing abuses of power by the federal government overall.
Things haven’t really worked out that way. Thanks to the rise of political parties, coordination between the branches — along party lines — has often replaced competition between the branches. Moreover, as political parties vie for the a controlling majority in the various branches, they are loath to limit the power of these institutions lest these partisans limit their own power in the process. Nor do the different branches represent different socio-economic groups in the manner imagined by John Adams in his Defense of the Constitutions.