IIN I'm weirded out by transgenderism?

The way I see it is, why bother being a dick? You say you don't care so why not just call them by the name they present themself as and move along? You can believe whatever you want but give others basic human respect. Put simply, it doesn't hurt you or anyone else to address someone as they want...but it definitely can hurt people if you refuse that basic courtesy. Why make someone's life worse when you could just smile, nod and move along and not make a big deal out of it?

I don't know the extent to which I believe upbringing and political ideology can turn someone LGBT.

You can find LGBT people in families across the political spectrum, and born into all kinds of backgrounds. I was born into a stable middle class Catholic home, with both a mother and a father who had moderate-conservative views, and I turned out gay. I've seen it all in other LGBT people I've met over the years, everything from the "stereotypical" gay raised by a single mom, to closeted LGBT people scared shitless because their families were conservative orthodox Muslims. Part of the high suicide rate with transgender people is because they're often not accepted by their families.

The only time I think it's politics is when you're talking about the stupid unicorn plum faerie Tumblrinas claiming stupidly nuanced genders. Those kind of people are always pretty far-Leftists, and them jumping on the bandwagon typically does say more about their politics than their actual life situation. They're all fourth-wave feminists.

I don't think it's any different than how non-trans people want to appear. Most people want to appear as they feel inside. You could probably empathise with a bio male who had unwanted large breast tissue...or a man who lost his penis in an accident...or a female who had thick unwanted facial hair. Now imagine it's your whole body that is 'wrong'. And it's not just to appear a certain way, it's how you feel, how you get treated, your personal happiness, mental health, etc.

There have been people raised as one gender but were actually the opposite. David Reimer is probably the most famous example (born male, lost penis as a baby, raised female) and it did not work out well for him. The psychologist who treated him was sure gender was all nurture and raising him female would be fine. It wasn't. His ordeal has spurred change in how cases like his are handled.

I think more liberal people are just more open anx accepting which is why you might think there are more LGBTQ people from such backgrounds/affiliations. Left/liberal politics is also the most concerned and progressive with LGBTQ rights. No mystery why an LGBTQ person might align themselves with that side. Religious/conservatives are generally less accepting and some are outright hateful of anybody who is different. This group is also typically against LGBTQ rights, or if not outright against them they are usually not 'pro', meaning they aren't actively helping progress and hinder progress by voting in officials who are not progressive in that regard because it's not seen as important to them. If you're LGBTQ, you'll probably either leave the group or stay in the closet, hence why you won't see as many.

what estrogen? where is your source for this?