This question is assuming that there is a prevalence of extreme views, especially since the age of the internet, and particularly in the last 10-15 years. It is not a blanket statement against all secular ideology or all views, more to do with when people specifically become possessed beyond the norm, in a way that brings them away from Torah views of Divine Providence, trust in Hashem, ahavat Yisrael (and isolating them from friends and family) and other mitzvot like don lechaf zechut, and can apply to both secular and "frum" people alike.
Please vote to close if you feel this is off topic, I can hear such an argument. I don't want to be controversial. It has been my experience though and I would love advice, especially advice that doesn't require one to be judgemental, or not kind. Halachic advice is the priority.
Once upon a time, the advice would be to stay away, and some people are still lucky enough that they are able to stay away without much effort (although simply staying away can be considered a cop-out, we are all responsible for each other).
Yet nowadays it's become very prevalent that many people buy into secular ideologies in quite an extreme, often combative/isolating way, e.g. vehement adherents of political ideologies - barely a month goes by that we don't find out one of our friends strongly believes and advocates for something extreme, including what appear to be conspiracy theories, and ideologies that are not provable but taken as fact.
Given that this seems to be happening a lot nowadays, what advice do people have for dealing with it? When at someone's house and one feels they are locked into a dangerous ideology, how do we talk to them? Do we smile and nod and avoid stirring the waters? Do we try to engage?
Main question: How do we deal with this while maintaining ahavat yisrael in heart and deed, being don lechaf zechut, and having kavod habriut and derech eretz?