This is actually not true. Trump denounced white supremacy many times (probably more than any other President in history). He even used those exact words.Yes, because Trump did not want to denounce white supremacy.
I always thought it was strange the DNC narrative was a bit like a Monty Python skit.
"I denounce white supremacy." "Do you can't denounce white supremacy?" "I do denounce white supremacy." "There you have it, folks, he refuses to denounce white supremacy."
This has been a fun year. The irony is there has never existed a political party so bent on racism and inequality than the DNC. But that is where they derive their power (slaves begging their masters for more chains).
The GOP is more dangerous, but the DNC is the party of social injustice.