I think it was about people becoming upset at seeing their communities change for the worse, seeing signs and publications coming up in spanish, seeing mexican names in headlines about high-profile crime, seeing mexicans use EBT (welfare) cards at the grocery, hearing anecdotal stories about traffic incidents where "a mexican hit me and had no insurance..", and seeing mexican gangs come to their town.
I think a lot of those voters felt unheard and tired of the politically correct excuses used to defend them. And when someone finally stood up and said "I'm going to fight this [ one precursor that enabled these changes] ", they were immediately sold.
(I'm not going to put an "I'm not a racist" disclaimer here, you all should be mature enough to interpret whether or not I actually endorse those stances or whether I am explaining the motivations of others who do)
Zuck building walls and buying islands to live alone and peace, without having slightest idea what is it to live in average neighborhoods who get to taste the immigrations bad (and good!) sides, while preaching no walls, no borders, mass immigration is good.
In other words, would we see the same political fervor from these people if they had a median income of ~150k/yr?
In favor of free trade: Cheaper goods for me.
It all boils down to "which collection of policies help me maximize my stuff?" Most people seem to take a more pragmatic approach, valuing tangible things over intellectual consistency.
With illegal immigration (wall) and H1B, you're describing the creation of a second class of workers within a country that depress wages within that country by having a separate, unequal workforce.
With foreign made goods you're describing a situation where workers from different countries have different protections, but those protections are consistent within the country.
Thats a big distinction to obliterate.
I'm all for actually open borders. Depress wages by allowing brown people access to the job market, fine. Depress wages by exploiting brown people and not giving them access to the same wages as their western counter parts, eh. It's intellectually consistent to be opposed to that.
If you find yourself reconciling the idea of protecting against wage competition from H-1Bs, but are in favour of continued undocumented immigration from Mexico (or at least opposed to taking any substantial measures against it), in favour of NAFTA remaining in place and in favour of continued trade with China under current conditions, I'd be very interested in understanding how you model that?
(There is also a critique around the specific rules of H-1B being unfair to the worker, mostly around restrictions on changing employers. I agree with most of that and don't think it inherently incompatible with other views on immigration and trade, pro or con.)