I think I will agree with what you say

"upper and middle class liberals and working class conservative Americans have bought the trickle-down theory sold to them."

I suspect that more regular middle class liberals don't buy into this. But especially those in quite well paid jobs I suspect have been strongly insulated from the effects of both free trade and immigration.

To them it is largely positive. They get cheaper stuff.

Technically I am much the same. As a software developer, I have not been affected by a huge influx of immigrants to Norway who work in restaurants, hotels, construction sites etc. But I am sure a lot of other people have been affected a lot by this.

I have personally seen positive things from this: Wider selection of different types of food. A lot more construction work done.

But I think I can see a lot more of the challenges since I live in an immigrant area unlike a lot of my peers which live in far more homogenous upscale neighbourhoods.