I would add that oblique approaches work better.

You can sort of assume that everyone on here has (a) played this game before and (b) already seen the day's talking points on the rest of social media. Re-litigating that here is just a waste of time. Your (2) is absolutely critical here; the bystanders will upvote posts that have links to good sources that tell them things they didn't already know. Which is good! That's what the site is for!

Also remember: you can't convert the person you're arguing with. But it's the (invisible) audience who are handing out the scores.