This was great to read. Definitely a perspective worth cultivating.
I disagree with your professor who “…once said the only way you can alter someone’s behavior is to make them feel guilty or ashamed.”

Shaming isn’t a very effective strategy for anyone over 10 years of age. When adults sense a threat to their preferred ideology, they rationalize cognitive dissonance and dig in. They will argue beyond reason to save face or protect in-group loyalties.
True change of heart comes from deeper understanding, which isn’t cultivated by guilt or shame. Rather, by instances of unexpected humanity from the perceived “other.”