Most people in the political world implicitly believe that persuasive arguments can win ideological converts. While disagreement reigns about what constitutes a persuasive argument, belief in the power of ideological evangelism—the practice of moving people from  one world view to another—is rampant.

Alas, the more we learn about the origins of ideological belief systems, the more untenable that idea becomes. A rapidly expanding literature on the origins of ideology demonstrate that 40 to 50 percent of the variation in political outlooks is rooted in DNA. Many of us are simply born to be liberals, conservatives, libertarians, or progressives. Political world views that cannot be explained by genetics can largely be explained by early childhood development. A recent study found that childhood personality characteristics (some of which are undoubtedly genetic, others, not) can predict political attitudes 20 years later. Personality traits—which are largely in place before ideological evangelists have a chance to make their case—are powerful predictors of political world views.

Accordingly, I am skeptical about the clarion calls we often hear to “make the moral case” in the course of promoting our policy ideas. If the “moral case” were that clear, there would not be any debate to begin with. It is only when the moral case is unclear or when warring moral considerations are at stake that we have room for a debate. Alas, given the origins of our attitudes about such matters, aggressively marshaling, say, the morality animating Robert Nozick’s libertarianism against liberals who implicitly hold John Rawls’s view of the world is unlikely to bear much fruit.

Ideological evangelism does have some utility. Some people are hard-wired to accept our world view but have not been sufficiently exposed to it. Expose them to it and we win a convert. Others lean in our direction but have not been provided the organizational super-structure to sort through conflicting political considerations. Expose them to our ideological super-structure and we win a convert. Appealing to widely shared moral values can positively frame issues.

Ideological argument alone, however, is not enough to carry the day with those who are not already in our camp. Just because those arguments appeal to us does not mean that they will appeal to others.