A fanatic has been defined as someone who can't change his mind and won't change the subject. It's a good description of Donald Trump, who began his quest for the presidency stoking fear of foreigners and used this year's final debate to keep doing it, as he has throughout his presidency.
Foreigners who come to America — with or without authorization — are viewed with hostility by this administration. It has diverted military funding to build Trump's border wall. It has separated thousands of foreign children from parents who came without permission — and then failed to reunite hundreds of these families. It has cut refugee admissions by some 90% and legal immigration by half. It has declared war on "sanctuary cities."