All you can do is present your case.
Everyone has an instant dictionary, thesaurus, encyclopedias, published articles, books, discussions, debates, etc....at their fingertips when arguing online.
You don't have to know anything about anything and can become an instant expert.
Need an article to defend your position.....Google and voila!! The instant "I told you so" without doing anything.
What I find funny is that most people don't even read the articles they put forth as a defense of their position.....as long as the header supports what they're saying that's good enough....the rest is just details LOL.