This turned into a care post, just a warning.
That "There's no such thing as a moderate/centrist" nonsense drives me up the wall. A moderate is someone who considers the arguments from both sides of the political spectrum, even if you don't agree with them in the end.
The best way to convince someone to change their mind is by understanding why they believe what they believe.
For example: I believe gun control should be stricter (probably requiring an amendment). But I at least understand why Republicans don't. A common refrain is "Good guys obey the laws, and bad guys don't; gun control would just leave the good guys defenseless against the bad guys." Well, ignoring the fact that most people are grey (and many shootings happen because otherwise decent people get heated), they're right. For a time. Drug cartels, robbers, home invaders, muggers, etc. would have black market guns while good people have no guns... for a time. Probably a couple decades. But the idea is that the black market is supplied by the legal market. If you cut off the source, eventually the black market for guns will dry up, too. It's different than drugs, because manufacturing capable weapons on a mass scale is much more difficult than growing weed. You need weapon manufacturing companies. Good luck keeping many of those under wraps for a significant amount of time. As a model, tight regulations on explosives has been very successful. You don't see widespread bombings here like you do in other countries, and even when there is a bombing, it's homemade. A number of psychos have tried to use bombs, including in Columbine, but because they had to manufacture their own, they failed, as many/most homemade explosives do. They don't have access to TNT sticks.
But yeah, I understand the right's argument. And that's why I've been so successful at getting conservatives to at least reconsider their gun control position, because I understand it. They don't want to go through potentially decades unprotected when the worst of the worst are going to have guns.
There are some that are worried about the gov't, too, but civilian weaponry is already so far behind the military's that we wouldn't stand a chance anyway, were things to go south. I think the bigger challenge for a potential dictator would be getting the military to follow orders to exterminate their fellow countrymen.
Anyway, I digress.
Another example: I'm anti-abortion. To me, that's a human life that deserves protection and is being killed by the millions. However, I understand the left's position. If you assume that the zygote/embryo/fetus being killed is no more significant than clipping a fingernail, then yeah, anti-abortion laws don't make sense. Understanding the left's position has allowed me to have successful conversations with many pro-abortion people, including one of my buddies who--along with his girlfriend--got an abortion at one point. I was successfully able to convey to him that I think the act of an abortion is morally reprehensible while still showing him that I cared about him and didn't judge him for the action. We had a long conversation about it. And while he went away not being convinced that I was completely right, he understood my position. He didn't see me as some evil dude trying to control women's bodies. He saw me as someone who took the life of the fetus into account when weighing the conflicting values, and coming out in favor of banning abortion. And he and I are still friends--even though I'm so anti-abortion and he had one.
Yeah, I'm a moderate. I exist, as do many, many others, and while you can close your eyes, plug your ears and say lalalala I'm right about everything and if you disagree with anything you're a nazi, that doesn't make it true. It just makes you a more limited, less effective person in affecting people's thoughts on social issues, and leaves your scope of understanding of many issues--and society--severely limited.