Some asked why she wasn't backing Mbali Ntuli, who is also contesting the top position, with some commenting that she is endorsing Steenhuisen because she wants to “make the DA white again”.
Others came to Mazzone's defence, saying Ntuli is “shooting herself in the foot” by criticising the party in public.
A few discouraged the debate about race, saying the DA's leadership conference should be about the candidates' qualities of good governance.
In response Mazzone said, “When all they can attack you on is the colour of your skin, you are winning.”
She also labelled some of her critics as “bots” and said she would not respond to their tweets.
She said she was backing Steenhuisen because she trusted his leadership for the future of the party.