If you move to San Jose your political views will be similar to the vast majority of people you meet in San Jose. Dallas maybe less so.
I think people in the UK sometimes don’t understand just how big and how diverse the US is. It’s more comparable to all of Europe than the UK. There is of course a big difference between living in London vs [insert small Scottish village name here]. But it’s very small compared to the difference between living in, say, Paris and a small town in Kosovo. Or New Orleans v Minneapolis. Or Honolulu v Anchorage. Or San Jose v Texas. They are completely different experiences. Some Brits have written off America based on one trip to Florida. been to Florida, not realizing that Florida has its own particular vibe/culture that is different than many parts of the US. People who say “Ive been to America and I didn’t like it,” if you didn’t get a good vibe from Benidorm or Athens or rural Romania would you write off all of Europe? Your loss I guess, but it’s a very small way to think.
There is gun violence in America, that is a fact and it’s it’s horrifying. But you need to keep it in perspective. Statistically speaking the risk of you being shot anywhere in America is infinitesimal. And the gun laws vary SO much from state to state so it will be different depending on where you are. I grew up in a big city in the northeast and I don’t think I’ve ever seen an actual working gun (other than police etc) in my life. Yet I live in the UK now and my family constantly worries about terrorist attacks. The extent to which you perceive risk can be completely different to the actual risk. Being killed in a car accident is FAR more likely than getting shot in Dallas or run over while standing on a bridge in London. Yet most of us get in cars every day without thinking twice.
Maybe I’m defensive bc I’m proud of my homeland but I’m not blind. The federal government is an utter shitshow, healthcare costs a fortune, and there’s little social safety net. I have lived in cities where racial tension is a real issue. These things are a worry. But there are worries here too. And in both the UK and the USA none of those worries in any way prevent me from having a great life with a nice house, great job, fantastic friends, wonderful educational opportunities for my children, and living in a beautiful city with easy access to world class skiing outdoor recreation.
Northern California is a fantastic place to live if you are a very high earner. Big cities with plenty of culture with easy access absolutely breathtaking natural beauty and outdoor recreation opportunities. I think California public (state) schools aren’t great overall but there are pockets of northern Cal where the schools are amazing, and you don’t have to worry about “getting in.” You move into the catchment for the school you want and they will enroll your child. You pay the price in property values but it sounds like that’s not an issue for the OP.
OP if you haven’t watched Big Little Lies you should. Obviously it’s a total caricature and it’s set in Monterey not San Jose, but it actually does in many ways capture and massively exaggerate the sort of lifestyle you may find in Silicon Valley. There’s a great deal of champagne liberalism and virtue signaling but it really is an amazing place to live if you are a super high earned (high six figures and up) or have other financial resources. People are generally friendly, and there’s enough diversity and turnover that it won’t take you long to fit in.
And just a piece of general expat advice — I STRONGLY recommend visiting for at least a week before you commit to any location. Your relo company will arrange school visits and property viewings and have someone to take you around. It’s helpful. And of course read everything you can online and talk to anyone you know who has lived there. City-data.com is a great resource with a lively chat forum— you will get unvarnished views about the pros and cons of Dallas v SJ or which neighborhoods in either city have good schools and whatever else you are looking for. I bet you could find a friendly corner of reddit that can help as well.
You should also find out exactly what your husband’s package will entail. Right now we are lucky in that my husband’s company pays our UK rent while we have tenants who cover the mortgage on our house in America. It’s a big windfall. The company also pays for private schools, regular flights home, visa costs, and the like. When we first moved they allowed us an air shipment so that we could get the essentials quickly and a sea shipment for anything else we wanted to bring — furniture, art, kids’ toys, bicycles, non-perishable foods, and more. They also covered moving and storage for anything we left behind. They even disassembled the swing set (climbing frame?) in our backyard and pressure washed it so it won’t rot in storage. They reimbursed us for preschool fees we had prepaid and the loss we took in selling a car we had recently bought, and gave us a one-time allowance to cover things we had to buy new, like lamps, TVs, and small appliances, or set up, like TV and WiFi. These are things that used to be standard in expat packages but these days are not guaranteed. Make sure the amount they are offering for housing is really enough to give you a comparable “level” home to what you have in the UK. Not necessarily the same size of course, as housing differs from one place to another. For the cost of a bog standard 3 BR in greater London or average bungalow in Silicon Valley you can get a palatial estate in Dallas.
Best of luck! Feel free to PM me if I can help any further. Personally I say move to San Jose!!!