What people need to get is that you really can't change someone's opinion. Argument is good because that's how things improve but when it comes down to trying to change people's minds it's just pointless.
It's possible to change people's opinions.
It just needs a fair amount of skill and work.
There are thousands of people who make a living off of changing peoples opinion.
Consider Lawyers for example.
If you're trained in the Oratorical arts then you'll have better luck changing peoples opinions.
Most people just have no idea how people actually respond to the way they tell people things.
So they end up surprised when someone ends up continually disagreeing, despite how much they shout at the person who's mind they want to change.
If there is one place I would love to back to and learn from, it would be Classical Rome and Greece, around 100 BCE, and I'd learn the skills of an Orator.