Bryan Caplan, one of the bloggers on one of my regular blog reads, has a great insight. When an irrational view has no personal consequences but feels good to have, such as when we argue about how great our favorite sports team is (when it really isn't all that), there is actually a net benefit of having the irrational view. We can happily let ourselves succumb to biases such as the confirmation bias to strengthen the view still further. We see the teams latest win as evidence of how great they are, but ignore their last seven losses as a streak of bad luck.
The problem arises when these all add up. There are many political views that we have very little impact on as individuals, but may feel good. For example various forms of protectionism. Even if the economics shows that free trade, open immigration, etc are good in the long run for the economy, it may feel good to blame your work-related stress on an anonymous worker or company in a foreign country. The more foreign, the better.
But what if thousands of people walk around feeling good about blaming these anonymous foreigners. Pretty soon, the politicians who really do have an effect on economic policies start listening. In order to get re-elected, they have to enact policies that are wrong. All of a sudden, these safe irrationalities have real consequences. A characteristic of our cognition that may have been evolutionarily adaptive now because damaging at the society-level.
What can we do about this? We can force everyone who wants to air their political views to get some policy education and really think about their views first. But of course, this is not realistic. I don't have a solution to this, but I am willing to hear proposals.