Lots of people like to claim fact to support their opinion, and that is generally a good thing – having factual support for the opinion that you hold. It does not, however, mean that your opinion is correct because you have a fact (or several) to cite.
Facts are data. Your opinion is your interpretation of how that fact came into being (cause), your opinion on how that fact has applied (effect) to the situation, and your opinion on how best to ameliorate that fact or situation you think it applies to (solution). Once you state your fact, everything else you spout is opinion. Understand that truth. Even if you have historical precedent that your opinion worked out one way in the past, it does not always mean that it will work out that way now, in the present.
Two people can see the same fact and interpret it widely differently based on the filters, experience, education, and logic they bring with them to interpret those facts, which they use to form their opinions.
Therein lies the rub, particularly when the issues that are being discussed are political ones, or social issues. Those are not simple issues, in part because they affect people of widely differing values, cultures, and circumstances. A solution that works for one segment of the population disenfranchises other segments – a truth that continually evades lawmakers.
I am apparently among the very small minority of people who can respect someone whose opinion differs from mine. I still do not think they are correct, but I can respect that they have some basis for their opinion in fact – exactly like I do. Even when I think they are completely wrong, and they have no basis in fact that I can determine, they are still a human being entitled to their opinion – exactly like I am. YES, it is best if opinions can be formed with factual bases, but understand even when they ARE, we can still legitimately differ in our opinions.
And *I* can respect that.