If you really want to talk about a controversial issue, step into the shoes of the person you are talking to. Why do they think that?
Because frankly, there is very little in this world that is entirely black and white. And there is a ton of political stuff that is not driven by evidence but by personal values.
And if you are arguing from a position of personal value, which most of us are – make sure you fully understand your own personal values. Why do you feel the way you do about an issue? What are the values that drive your emotions on the issue and how does the position you have taken support them.
Try to understand the values that drive the position of the person you are talking to.
Because honestly, for most people evidence will not weigh heavily against personal values. People will cite evidence all the time, but the evidence is not why they support their viewpoint. The personal values are the reason. The evidence is used to support a position they took long before they even knew the evidence existed.
And before you discuss an issue and cite evidence, please look up your facts. Check your sources and if all of your sources come from the folks who are heavily endorsing your political viewpoint, look a little deeper.
People who are politically invested with a lobby are not your most reliable source of material.