Possibly the oldest human worldview is fear of strangers. And right next to that is anger as a byproduct of fear.
If a candidate wants to gain attention and possibly votes, then, it makes short-term sense to stir up fear of strangers and turn it into anger. It might even work (once). But it makes it virtually impossible to govern. It's a short-term strategy that eats itself, because sooner or later, everyone is a stranger, and fear is no foundation for work that matters.
It seems as though we're entering a season in which it's easy to ostracize or become righteously indignant over someone's national origin, skin color, religion or sexual orientation.
If this is the best a politician can do to organize and lead, then we all lose.