Proud American bigots will not own their bigotry. Even most KKK groups deny they are racist (though they clearly are). 'Racism' is a fighting word in the US. Try telling some Trumpeteers their approach to Latinos is racist, and see what happens.
The US is full of active and systemic discrimination, including very strong racism, but we don't want to acknowledge it. We don't want to talk about it. We don't want to change it, unless and until it is seen as directly harming rich, white people. Then, maybe we'll consider halting the war on drugs, or at least pot.
Many of us don't want to admit historical tidbits like slavery, Japanese internment, the terrorist civil war that lasted 30 years after the Civil War (which the south won), race riots, Indian wars, or imperialism. Calling racist policies and acts what they so clearly are is perceived as an insult to those who craft them and carry them out.
We definitely do not want to think about how redlining was started by our federal government and continues today thanks to banks and realtors. We can't conscience a connection between a racist past and what's going on today. That might mean racism still exists in the US, and we might be abetting it or at least letting it slide. That would make us bad people, because racism is bad. And we are not bad people. We live in the greatest country on earth.
Rather than being proud of their racism, Americans are scared of it. We are like alcoholics who angrily declare we don't have a problem whenever confronted with evidence of our disease.