Libertarians sometimes accuse progressive liberals of not being able to see the hidden costs of particular policies or activities. In one sense, this is true; since most progressive liberals don’t understand basic economics, they often have difficulty understanding why libertarians scream about deadweight loss.
In another sense though, it’s not true that progressive liberals ignore hidden costs. For example, in the case of the oil spill, leftist environmentalists had long advocated for the government to reduce or even ban offshore drilling. They were concerned about a specific kind of hidden cost, the cost of environmental problems. The problem is that they either exaggerated those costs or somehow didn’t really care about rationally and honestly weighing costs and benefits. Belonging to the Church of Unlimited Government, they tried to sell ever more government involvement with ignorant or dishonest assessments that the environmental costs were higher than the benefits of cheap energy.
I am being charitable here and even giving the leftist environmentalists the benefit of the doubt by assuming that they do in fact weigh costs and benefits. It is more probable that these folks, guided by their intuitions, ignore costs and benefits. Economists are hated for their utilitarian calculus by pointing out the the optimal number of fatal car crashes is not 0. Getting the number to 0 would require a blanket ban, thus forgoing the vast benefits of driving. It’s not romantic to weigh costs and benefits; people would much rather cling to the delusion that social problems can be absolutely fixed. Alas, that’s the Nirvana fallacy.