A fundamental question for democracy is what should be submitted to the democratic process. The laws of physics are presumably immune. But should public opinion help to decide which areas of science are studied or funded?

That is the implication of an amendment to the 2013 spending bill for the US National Science Foundation (NSF), which was approved by the House of Representatives in May. The amendment, proposed by Jeff Flake (Republican, Arizona), would prevent the NSF from funding political science, for which it awarded about US$11 million in grants this year. The Senate may well reject the amendment, but it is troubling that it has got so far, for two reasons.

First, to target a specific research programme marks an escalation from the familiar trick of finding research projects with apparently trivial titles and parading them as a waste of taxpayers' money. And second, scientists should ask themselves which vulnerable research programme could be next on the hit list — climate-change education, perhaps?

The idea that politicians should decide what is worthy of research is perilous.

The social sciences are an easy target for this type of attack because they are less cluttered with technical terminology and so seem easier for the layperson to assess. As social scientist Duncan Watts at Microsoft Research in New York City has pointed out: “Everyone has experience being human, and so the vast majority of findings in social science coincide with something that we have either experienced or can imagine experiencing.” This means that the Flakes of this world have little trouble proclaiming such findings obvious or insignificant.

Part of the blame must lie with the practice of labelling the social sciences as soft, which too readily translates as meaning woolly or soft-headed. Because they deal with systems that are highly complex, adaptive and not rigorously rule-bound, the social sciences are among the most difficult of disciplines, both methodologically and intellectually. They suffer because their findings do sometimes seem obvious. Yet, equally, the common-sense answer can prove to be false when subjected to scrutiny. There are countless examples of this, from economics to traffic planning. This is one reason that the social sciences probably unnerve some politicians, some of whom are used to making decisions based not on evidence but on intuition, wishful thinking and with an eye on the polls.

What of the critics' other arguments against public funding of political science? They say that the field is more susceptible to political bias; in particular, more social scientists have Democratic leanings than Republican. The latter is true, but it is equally so for US academics generally. We can argue about the reasons, but why single out political science? The charge of bias, meanwhile, is asserted rather than demonstrated.

So, what has political science ever done for us? We don't, after all, know why crime rates rise and fall. We cannot solve the financial crisis or stop civil wars, and we cannot agree on the state's role in systems of justice or taxation. As Washington Post columnist Charles Lane wrote in a recent article that called for the NSF not to fund any social science: “The 'larger' the social or political issue, the more difficult it is to illuminate definitively through the methods of 'hard science'.”.

In part, this just restates the fact that political science is difficult. To conclude that hard problems are better solved by not studying them is ludicrous. Should we slash the physics budget if the problems of dark-matter and dark-energy are not solved? Lane's statement falls for the very myth it wants to attack: that political science is ruled, like physics, by precise, unique, universal rules. In any case, we have little idea how successful political science has been — politicians rarely seem to pay much heed to evidence-based advice from the social sciences, unless of course that evidence suits them. And to constrain political scientists with utilitarian bean-counting undermines the free academic nature of the whole exercise.

The idea that politicians should decide what is worthy of research is perilous. The proper function of democracy is to establish impartial bodies of experts and leave it to them. But Flake's amendment does more than just disparage a culture of expertise. The research he selected for ridicule included studies of gender disparity in politics and models for international analysis of climate change — issues that are unpopular with right-wingers. In other words, his interference is not just about cost-cutting: it has a political agenda. The fact that he and his political allies seem to feel threatened by evidence-based studies of politics and society does not speak highly of their confidence in the objective case for their policies. Flake's amendment is no different in principle to the ideological infringements of academic freedom in Turkey or Iran. It has nothing to do with democracy.