system
Given the following post, respond as if you're commenting on Reddit:
human
CMV: People become more conservative over time because they change, not because the issues change

A big part of this opinion comes from my experience of having a liberal left-wing father turn into a Trump supporter, so  here's a bit of background information about what happened. My father lived under Maoist China as an adolescent and immigrated to a Western country (not the US) when he was a young adult. Needless to say, he became fascinated with politics since he was a teenager, as a result of living under a country where political ideology permeated every part of everyday life. As a result, he's always had quite a bit of cynicism towards socialism but that's another story...

Anyways, when I was growing up since the age of 8/9, he would tell me stories about history and politics and we would watch the daily show with Jon Stewart quite regularly. Even though I didn't quite understand everything that was talked about, my dad was always a huge fan of Jon and that greatly influenced me with me being a liberal democrat currently (used to be a big social democrat)...

He hated Bush Jr (still does btw, he remained consistent on that), and loved Obama. He would show me clips of Obama speaking with his inspiring "yes we can" slogans, and he even tried to help me with my public speaking problems/stage fright, by showing me tips Obama gave on addressing an audience. When Jon was nearing retirement, we'd watch the last week tonight show with John Oliver together instead.

 But I could see over time, that his appreciation for liberal ideas lessening. He became more and more disillusioned with Obama, going from slight disappointment, to seeing Obama as a weak willed failure and a sell-out. Around this time was also when Trump first announced his run for presidency. We both took him as a joke originally, but as time went on and the Republican primaries went down to just a few candidates, my father became more and more sympathetic and supportive of Trump. We'd have endless fights over it, with me feeling a little betrayed that my father had abandoned the ideas and values he had raised me on. 

After Trump won the presidency, my father only became more and more of an ardent supporter but he knows that me and him disagree so he tries to bring it up as little as possible. However, every once in a while, the topic comes up at the dinner table, and it usually ends with both of us steaming off and not talking to each other for the rest of the day. I've tried to become more calm about it and so has he. 

We've talked about why he really supports Trump, and a lot of it just comes from this jadedness and cynicism towards the system that he projects from a lot of the regrets of his own life and a lot of the dreams that never came to be as he grew older....I confronted him about that, and he just replied "you wouldn't understand, until you've lived a life where all the dreams and optimism you currently have now, are shattered when you get to my age". For him, he supports Trump no more than he sees Trump as a protest vote, a way to say f\*\*\* off to the establishment and the political elites and a system that he fought for in his youth, which only abandoned him when globalisation came around. A middle finger of sorts to the upper class liberal establishment that advocate for political correctness and telling people what to say, think or who to vote for (as he puts it)....

I asked him why he doesn't support Bernie then, and he said basically Bernie didn't have strong enough views on social issues and he didn't like how Bernie called himself a socialist...He thought it was insulting to all the suffering people under past socialist regimes had to deal with. (Father's very anti-illegal immigration, doesn't really like multi-culturalism but is very pro-choice on abortion, very pro gun-control, and about as tolerant of lgbtq a boomer from socially conservative china can be) He almost swapped sides because of Trump's refusal to do anything on gun control...

Sorry if this was really long, and if it came off a bit like just venting...but I've been thinking about this a lot and it just seems to me most people don't have any fixed political beliefs and rather just position themselves according to the where the Overton/normal discussion window is currently. A progressive who fight for the goals of today, will still fight for new progressivist goals if they were born after all the current day goals have already being met. 

Similarly when someone gets older, they change, they care more about stability and security, become more cynical, jaded and no matter which  direction the issues have shifted in comparison to their youth, they will align themselves with the conservative side of the overton window. (Not talking about everyone, just commenting on how quite a majority of the demographic become more conservative as they grow older)
gpt
It seems your father wanted change and was upset when Obama didn't fulfil that promise.

Now he seems to be supporting Trump for that very reason.

That doesn't necessarily seem like has become more conservative, more that he feels Trump is more likely to deliver the change he wants.

In the end though, he's ultimately going to be disappointed.

Maybe try approaching it from that angle?