They fear becoming a minority.
They operate under the false beliefs that they already are and that “the libs” bring in foreigners to tilt the vote (which is litteraly not possible) and then “those people get free everything” to feed further into racism. The imaginary bussed in people can’t vote or get benefits but thier social circle says so and thats all they need to believe and repeat it.
The triangle of rhetoric is appeal to authority, appeal to emotion, appeal to logic. They don’t accept any of it thay didn’t come from within thier social group so there is no convinving them and that is why Tronald Dump can say he could shoot somebody on 5th avenue and have them call it fake news despite being recorded.
(Edit x 5 :Why oh why can’t spellcheck just work?)
Even when you do manage to get one to think and realize the truth their peer group will come down on them HARD for “falling for leftist propaganda” and they will 180 immediately.