Republicans have a huge and extensive propaganda network that feeds their constituents a steady stream of misinformation, fear, hatred, intolerance, and ignorance. Fox News primes them, Republicans parrot Fox or whatever right-wing news outlet people get their news from, and get elected because most people don't have the media literacy to see that they're being lied to.
We can't reason with them, because they live in a world that has been carefully crafted to keep them compliant. The only way to fix this is to break the GOP's propaganda machine. Until we can do that, they are lost to us.