Politics is a very precarious subject, and should always be treated as such. The vast majority of people personally identify with politics, similarly to how people personally identify with sports teams. Criticizing another person’s political opinion is the same, to most people, as simply attacking their character. You need to do these things:
Establish Common Ground.
Politics is almost always the discussion of how to go about helping other people. You disagree with another person’s political viewpoint because you don’t agree that their way is the best way to help people, and they disagree with you because they don’t agree that your way is the best way to help people. The common ground is that you’re both trying to help people. The problem that often occurs is that one party assumes that the other party does not want to help other people.
Someone supports Trump pulling out of the Paris Climate Agreement? Do not assume that this person does not care about the environment. Someone disagrees with the welfare system? Do not assume that this person disagrees with helping the impoverished. Sociopaths probably don’t even feel strongly enough to enter a political discussion, so never assume that the other person is one. They most likely just want to go about solving those problems in a different way.
If a stark disagreement arises, readily establish that you understand that the both of you simply want to help other people, and that you commend them for doing so; you just believe it should handled in a different way. Then go about supporting your position to the best of your ability.
For example: “I understand that you disagree, but I know we agree on this: we both want to fashion a society that is preferable for the most amount of people and limits suffering. We both just want to help people, and I think this will help do just that…"
Even if they disagree with the rest of that statement, they will still commend you for that intro. It will eliminate that voice in the back of their mind that’s telling them you are a saboteur.
Understand Who You’re Dealing With
Arnold Kling wrote a book called The Three Languages of Politics, and I recommend everyone read it. He identifies three separate languages being spoken in modern political discourse.
The Republicans speak the language of Barbarism vs Civilization- where there are generally always groups of people who want to corrupt the fabric of society vs their group that wants to preserve society. They often look to the freeloaders, the criminals, and sometimes (but not always), foreigners as the corruption of society. Their entire worldview rests on this premise.
The Democrats speak the language of the Oppressed vs The Oppressors- where there are generally always groups of people, usually small but powerful groups, who are oppressing the rest of society. They look to big business, specific parts of government, and the wealthy in general, as the oppressors and that everyone else is being oppressed in some way. Their entire worldview rests on this premise.
The Libertarians speak the language of Liberty vs Tyranny- where government is generally always moving in the direction of tyranny, and everyone underneath government is generally being stripped of their liberties. They look to most government action as impinging on the freedom of its citizens. Their entire worldview rests on this premise.
You always have to understand what kind of person you are dealing with so you can best address their concerns. When a Democrat tells a Republican that the poor are being oppressed, he has a hard time speaking that language. From the Republican’s worldview, this is not the main problem, the main problem is the freeloaders on welfare. And the Libertarian has a hard time understanding both of them, for of course the real problem is government!
You need to fashion your argument in such a way that it is understandable by the other person’s worldview, or all worldviews. Establishing common ground (like discussed above) helps to do this, but you should try to speak their language. Ask the other person why he believes his issues are more important, who knows; maybe they have a point. Try to agree on as much as possible, but not so far as to disagree with your own principles.
Simply because we speak different languages does not mean we are all correct. People can hold very irrational beliefs, and, of course, its usually the other guy. You do not have to respect someone else’s beliefs, but remember, you are both arguing about helping people. Never let these disagreements rouse anger.
Be Kind
This is not a critical discussion of their character! You are simply a critic of their specific belief. Being kind is always respectable, and being angry is not. Remember that you are both discussing the best manner in which to help society.
“There is nothing more stupefying than anger, nothing more bent on its own strength. If successful, none more arrogant, if foiled, none more insane- since it’s not driven back by weariness even in defeat, when fortune removes its adversary it turns its teeth on itself.” — Seneca, On Anger
Don’t Expect Them to Concede
There are some of you who are thinking, “But, I actually am right. I am the rational actor here, and the other person is dogmatic and irrational. I am actually right, they are actually wrong, and they won’t accept it!”
As Marcus Aurelius said, “It’s silly to try to escape other people’s faults. They are inescapable. Just try to escape your own.”
Just because they won’t concede doesn’t mean they are not wrong. Humans are prideful, and accepting defeat is a hard thing to do. Let them think about your words for a while, people are rarely swayed by one conversation. Deep beliefs change slowly. Who knows, maybe they’ll come around to your way of thinking eventually.
Or maybe they don’t care what you think. Oh well, you tried your best to kindly change that person’s belief, and that is all that you can do. There’s no reason to hold a grudge or to blame, for why would you blame something that’s outside of your control? You don’t curse and blame gravity every time you jump, do you? Why curse the opinions of others, there’s nothing you can do about them. If you didn’t convince them, blame yourself, or blame no one.