|His point here is a great one, that "pragmatism" as applied to foreign policy is little more than another term for realpolitik, the amoral pursuit of national power in a competitive and adversarial nation-state environment.
There is another fundamental problem with the ideology of pragmatism (yes, "I hate ideology" is an ideology too!) - that can be expressed as a question: What goals do these pragmatic policies advance?
At a conceptual level, ideology is a simply a heuristic for selecting the best path in problems without an obvious or easily discerned solution. So you "guess." You pick a method that, though not guaranteed to solve every problem, hopefully makes them no worse, and maybe leads to other desirable side-effects even if the core problem remains.
Apart from politics, you might have a rule-of-thumb that says "always retrace your steps from yesterday evening" if you can't find your keys. Others may "always search some list of locations consecutively." There may be no single "correct" approach for every time you lose your keys.
When it comes to picking your political ideology, the decision (to the extent it is a conscious decision) will hinge on ethical and philosophical questions not relevant to car keys. Nonetheless some of the same principles apply. You pick, say, libertarianism, because you think it solves problems well, and provides an appealing approach to the large and intractable problems of "how to govern and organize humans." Libertarianism won't just find your car keys, but brings the world closer to the ideal where it is impossible to lose keys because magic markets solved that problem somehow. Ideology entails both a specific solution to a specific problem, but also a general approach to larger challenges.
Two people with differing ideologies will often find they have very different interpretations of the outcome of a policy (assuming they agree what the outcome was), because they desire different ends. Conservatives like the Bush tax cuts because they got extra money. Liberals dislike them because they helped grow the gaping income chasm between rich and poor. This is not a "downside" to conservatives so even if they acknowledge the rich got more money, they will respond along the lines that these people worked hardest/smartest or that a vibrant wealthy class are creating jobs etc with their excess capital. Forget the merits of these arguments, the point is to illustrate that these two ideologies cannot reach a "pragmatic" solution on taxation, since they do not agree on a fundamental level about what the tax system should be doing.
It is possible to find areas of goal alignment between two ideologies. If communist hordes are parachuting into town a la Red Dawn, liberals and conservatives will agree to "stop them." More realistically, conservatives and liberals do generally agree (at least nominally) on some goals, like technological advancement or economic growth. Even so, it is quite difficult to find specific policies that advance these goals which would be supported by both liberals and conservatives. Sometimes this is because neither side agrees the others' approach will work on the problem at hand, but in others they will oppose it because it brings the system further from their vision of ideal. Thus, liberals will oppose strategies for economic growth which harm the environment or disadvantage minorities.
The point is not that pragmatic solutions should be reflexively opposed in favour of ideologically pure liberal approaches. That is largely a myth of the bi-partisan beltway crowd who value civility over decency and believe in some magical era where all legislation passed unanimously. Such problems are generally handled quickly and without rancor, because everyone already agrees with the solution at hand.
Ideology is not a dirty word. "Ideologue" may be, but they're not the same thing. Without it, we are adrift in a sea of problems, without a compass or a destination in mind.