He doesn't have a good answer. He thinks ideas I'm expressing are dangerous and so they deserve contempt. The truth is he may be a whole lot smarter than me but I think I'm more mature.
Your respect for your father's intelligence is admirable.
Conservatives used to say that we thought liberals were misguided, while liberals thought we were evil. This liberal insistence led to, for example, Ted Kennedy's "In Robert Bork's America" speech, and diminished the character of civil discourse years ago, although only from one side. The Republican thesis for many years, represented most clearly by the Bush family, was to "rise above" the rhetoric of the left.
Trump as antithesis inevitably emerged. The conventional wisdom in the media is that Trump has unilaterally diminished the character of civil discourse; I'm not a Trump supporter, but he is not guilty of this charge, he just expresses himself inartfully and with his characteristic narcissism.
People cannot respect each other's views because we view the opposing views not as misguided or simply different, but as evil. The liberal side started this, the progressives are pushing it to new extremes, and conservatives are finally recognizing this reality and adopting the same terms.
I have to deal with some of this in my own family. My blood kin get a pass - not to maintain without challenge stupid and destructive ideas, but to stay in relationship with me while doing so. Otherwise I limit my association with people who are convinced that my beliefs are evil.