During this stage, you need to relentlessly ridicule and tear down their arguments in the public eye, using both humor and logic. The first is more important than you think, arguments aren't won via logos alone.
> muh can't consent
> marriage is between a man and a woman too, amirite?
or
> "i'm sure you only have sex in the missionary position for the sole purpose of procreation"
Remember the "ethics in gaming journalism" meme? It worked, and fucked up #Gamergate bigtime. I know, because I was there when it happened.
Before you ask, no, i'm not a pedo- and I think having sex with kids is absolutely disgusting. However, i've done my own research and come to the conclusion that you guys are morally in the right, even though I don't agree with you. The problem isn't with you, it's with the way society views sex as an inherently sinful thing. You should hammer home the point that that's a judeo-christian moral view not supported by evidence, and it's one that not every culture agrees with.
>Separation of church and state: We can't make laws off of religious judgements.
>In a diverse, multicultural society, it's unfair to prioritize certain minorities over others.
I like rooting for the underdog and defending unpopular opinions just to see where it goes. It doesn't get any more unpopular than you guys.
So, to continue: Never underestimate the power of pointing and laughing.
First, shift the burden of proof. Like so:
"The only issue at play here is whether these relationships cause MASSIVE and IRREVERSIBLE catastrophic psychological damage every single time! It doesn't matter how it's done, what circumstances it was done under, or the amount of violence used, but the very act of sex itself is so vile, so disgusting, so impure that it alone literally destroys children from the inside out, as you claim.
>Do you even realize how stupid this sounds? (Pointing and laughing)
First off, let's admit that there are shitty people out there who will take someone's love and do horrible, unspeakable things to them in return. It's sick, it's disgusting and it's wrong. It should be punished under the full extent of the law. But does it make sense to blame the act itself, rather than the people who commit it?
Unless you can prove something is universally harmful in every single case then you have no standing. In the 21st century (subtle appeal to modernity, implying that the person against it is behind the times), we don't punish people for who they are, but what they do.
It doesn't matter if you think it's wrong, or gross, or icky. Children's rights don't end where your feelings begin, especially if it doesn't involve you. (A meme and good slogan)
If you don't believe this, then maybe you shouldn't be behind the wheel of a car. Cars regularly kill more people than guns each year, so should we punish the use of cars? No. (Logic)
We punish the people and not the act of driving itself. What's so hard to understand about that?
Even if you want to go the "two consenting adults" route and claim children cannot consent, it still isn't your call. It's not your child, and it's not your job to protect them from the world. Leave that to the families and the children themselves. (Appeal to personal liberty and freedom). In either case, you seem awfully concerned with what people are doing together inside the bedroom". (None of your buisness)
More strategies and arguments coming up.