Chris Dillow, who is always worth reading, points out that there are incentives for politicians to remain ignorant.
Incentives dictate that, quite often, ignorance is better than knowledge.
Ignorance may but instrumentally superior to knowledge in some instances but it is not morally better than knowledge. Morally, we should not harm innocent people, or permit others to harm them. But we cannot fulfil that duty unless we know what would harm them and unless we know who the innocent are. In other words, we need to believe truly in order to act rightly. So, we need to try to acquire relevant true beliefs before acting, and to eliminate relevant false beliefs, if we are to do what we ought to do.
It is even more important for politicians to do this than it is for ordinary citizens. The actions of politicians are likely to affect more people and politicians really ought to do what is in the best interests of everyone who is affected. Politicians have less of an excuse than ordinary people for failing to do this, because they have more resources for research.
Of course, there is a great gap between what is and what ought to be. But that does not alter what ought to be.
So, what should a non-politician do? A good first step is always to try to acquire relevant true beliefs, and to reject relevant false ones. The second is to judge politicians by whether they do the same or not.
People like to deride politicians as dishonest. But they also let bigotry, partisanship and self-interest determine what they believe. Corruption begins at home.