The way I saw it, the "build a wall" campaign was more about mobilizing the frustration many felt about cultural changes and (perceived) social costs of illegal immigration and less about "they're taking our jobs" (though I'm not saying that argument was never made).

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)