The denial of "racist bones" by those accused of doing or saying something racist has a long history.
The problem is that “I don’t have a racist bone in my body” only makes sense if your definition of racism stops at personal animus. If that’s true, then yes, I’m sure that most people lack racist bones.
But let’s broaden our horizons a bit. If we think of “racism” as material harm—or anything that furthers racial stereotypes—then it doesn’t require anyone to hold hatred or show explicit bias. Bob Dole’s support for the South African regime wasn’t racist because he hated Black people; it was racist because it bolstered a racist government. Likewise, if Paul Ryan committed a racial offense, it was to perpetuate ugly ideas about low-income Black men.