Plenty of people have good reasons to support tariffs. Free trade destroyed a lot of industries and adjanced communities and the free trade fans didn't give a damn about them.
Silicon Valley didn't care about the rust belt, so why should the rust belt care about SV?
Aren't most things Americans buy imported or contain imported parts (for example all electronics)?
Won't a decrease in exports, because of other nations ti-for-tat tariffs, decrease wages for many US workers?
They won't, and they can't, and they certainly can't do it immediately. It takes decades to build up the manufacturing efficiency and processes to compete with China. We lost all of it.
We will continue to buy from China because it will STILL be cheaper. And your goods will be 3x more expensive, and that's the best-case scenario for a lot of goods.