There are careful studies (Kolko, Barnet, others) that provide details about what is pretty obvious on the surface: the executive is largely staffed by representatives of private power concentrations, law firms that cater to their interests, outsiders who gain a role because of their willingness to serve those interests (the Kissinger types).
Congress is somewhat more differentiated, but not a great deal. The average Senator, on leaving office, is unlikely to return to work as a truck driver, secretary, etc. More likely to a law firm, business, or other sector that draws from the higher levels of concentration of wealth and power. We don’t have the kind of political system in which mass popular organizations can elect their own representatives, like Brazil (or Haiti, to take an important case, which quickly led to a military coup). Funding of electoral campaigns has been extensively studied. The major work is by Thomas Ferguson (see, e.g., his Golden Rule), more generally, his “investment theory of politics” which holds, and is empirically well supported, that political choices are pretty well predicted by the way investors coalesce to invest in controlling the state. The information system consists overwhelmingly of corporations that share the same values and commitments: corporate media, PR system, etc. It’s been close to a truism for a long time that as long as there is an enormous concentration of private power, unaccountable to the public, politics will be hardly more than the shadow cast by business over society, as America’s leading social philosopher, John Dewey, put it long ago. In the absence of popular democratic structures — unions, functioning political parties, etc.) — how could it be otherwise.
There are no “conspiracies,” and it has nothing to do with “brutal men.” True, individuals influence decisions, but within a very narrow framework of choices… And that framework very largely derives from the concentration of domestic power, not surprisingly. That does leave a range. Thus the people around Bush happen to be committed to an unusual extent to serving very narrow concentrations of wealth and power and transferring costs to the great majority of the population and to future generations. Looking at who they are, and where they come from, it’s not hard to understand their role at the extreme of a pretty narrow spectrum.