Considering the amount of people who are against the idea of building an expensive US/Mexian wall in the US, even among people on the right (for financial, efficacy, etc reasons), I doubt immigrants would expect life to be much different in the US. Besides maybe Mexican immigrants who may join communities affected by policies limiting illegal immigration at the southern border.

At least from a cultural perspective for the majority of legal immigrants I'm sure day-to-day life isn't much different than before the wall plan. There are still more than enough good people in the US. Especially in urban areas where most immigrants end up.

As someone who has applied for an American Visa, my main concern would be more about the available Visas suddenly changing after I've established a life there. The process is quite complicated and stressful, and the T1 visa was the most common one for my type of work. For T1 you had to get it renewed each year.

That was a concern even in a pre-Trump US. The immigration policies there definitely need some work. And have for a long time. I was happy to see Trump saying he was looking at Canada's immigration policy (where I'm from) as a good example.

It will always be stressful for legal immigrants when the immigration policies are currently in political flux.