I've frequented several political fora, and The Politics Forum (TPF) is my current home. Most of the other members generally behave like adults, and are capable of accepting that others might have different views. That being said, TPF is an avowedly conservative forum; progressives are welcome if they behave themselves and avoid trolling or insults.
Moderation is very light, and the moderators generally let the members sort out their own disagreements; trolls, however, are not suffered gladly, or for very long.
The overriding ethos of TPF is individual liberty and equality - not so-called "equity" which is nothing more than racism in another word - and the members that that seriously.