Why is it considered racist to criticize MLK or Obama?

InsecureLivesMatter

My dad is a Trump supporter to the core, or at least that's what he says. He doesn't necessarily have conservative values. He is a total pothead. But let's be real, I stitched (replied) to a video on TikTok literally agreeing with a Black/African American woman about the truth about Martin Luther King Jr., and my dad suggested I delete the video. So he called me, asked me if I deleted the video and he told me not to bring up anything about race or other people's nationalities/ethnicities/colors that aren't our own. Because those other people will see us as racist if we do. And my dad says that's like black people talking about white people, they don't do that or else they'll be canceled.

My mom is a Trump supporter too, but they are completely different types of Trump supporters. My mom is a spiritual Christian-type maybe semi-conservative (but pro-choice); my dad is a Christian as well but not as vocal about it, and definitely more of a masculinist libertarian. Both have a thing against transgender people's rights in some ways.

Updates
10 mo
I explained to him that corporations often talk about Black History Month and AAPI Month and things like that and he told me, "Yeah but still." He gets pissed at me whenever I say anything regarding race online. He says he's a Trump supporter and wants him to win in 2024, but I highly doubt he embraces any conservative values.
Why is it considered racist to criticize MLK or Obama?
1 Opinion