A “political opinion”, at least in my parlance, is a system of beliefs which includes personal preference for a particular political party or ideology. “It is correct to adopt libertarianism” might express a political opinion. “The number of Jews killed in the Holocaust is about six million” is perhaps evidence that the speaker isn’t a typical Nazi, but it is too narrow and concrete to be called a political opinion per se.
As for the reasons why the caution applies to political opinions while does not (that much) apply to simple questions of fact even if they have political implications, consider how many obvious fallacies one has to commit to give a wrong answer. “How many Jews were killed in the Holocaust” is a question of fact with pretty straightforward meaning. Every reasonable person would agree that one should look into the archives and population censuses. Practically the only way to credibly justify an incorrect answer is to postulate a conspiracy which has faked all official evidence—and this is what actually happens. Then everything you need is Occam’s razor: conspiracies are complex and therefore very improbable.
On the other hand, when considering the question “is it correct to adopt liberalism”, both “correct” and “liberalism” are open to wide range of interpretations and there is no universally agreed upon method of answering this sort of questions. The biases have much easier role here in their effort to sway the result towards the prejudiced answer.
A “political opinion”, at least in my parlance, is a system of beliefs which includes personal preference for a particular political party or ideology. “It is correct to adopt libertarianism” might express a political opinion. “The number of Jews killed in the Holocaust is about six million” is perhaps evidence that the speaker isn’t a typical Nazi, but it is too narrow and concrete to be called a political opinion per se.
As for the reasons why the caution applies to political opinions while does not (that much) apply to simple questions of fact even if they have political implications, consider how many obvious fallacies one has to commit to give a wrong answer. “How many Jews were killed in the Holocaust” is a question of fact with pretty straightforward meaning. Every reasonable person would agree that one should look into the archives and population censuses. Practically the only way to credibly justify an incorrect answer is to postulate a conspiracy which has faked all official evidence—and this is what actually happens. Then everything you need is Occam’s razor: conspiracies are complex and therefore very improbable.
On the other hand, when considering the question “is it correct to adopt liberalism”, both “correct” and “liberalism” are open to wide range of interpretations and there is no universally agreed upon method of answering this sort of questions. The biases have much easier role here in their effort to sway the result towards the prejudiced answer.