90% of the arguments I'm involved in are hard core debates about whether or not somebody should get the death penalty, they involve a lot of shouting and I'm normally the one going "That mother fucker killed 3 kids, then drove 16 miles and robbed a gas station, fry his ass!" so, my opinion on things like that rarely change. My opinions rarely change in arguments anyway, it's not that I'm too ignorant to see the other way, I generally build my own conclusion starting from a neutral stand. I just generally feel that my opinions are worth sticking to.
Some things I'll waver on from time to time. It was my opinion once that joining the military would be cool. I talked to a bunch of military guys who hated it, every second of training, but thought it would get better. I don't think it's cool anymore, but I still want to do it, to serve and not just to say "Oh yeah, I killed 13 dudes," which is a terrible thing, I can't imagine doing it in any other circumstances than they're trying to kill me.
I've noticed that the more logical the argument, the more people will consider the other side. Once shouting gets involved it all just devolves into each person feeling naturally threatened and taking the natural position, defense. You might notice a flaw in logic on your part from time to time, but damn it, they'll never know because they can't win. As soon as they pause for breath, you jump on the offensive and batter their argument, it goes back and forth.
The latter, louder, argument is how most holidays end up over here, everybody debating something.