"It has been brought to the attention of Miss World America 'MWA' that you social media accounts contain offensive, insensitive and inappropriate content," the letter said.
It also said that Zhu no longer met the requirement of "being in good character." "Therefore, and effective immediately, MWA does not recognize you as a participant of any sort or in any capacity as it relates to any and all events of MWA," it concluded.
The social media posts were targeted at Muslim women and gun violence in the black community.
According to screenshots obtained by the Orlando Sentinel, the first tweet said, "There is a 'try a hijab on' booth at my college campus. So you're telling me that it's now just a fashion accessory and not a religious thing? Or are you just trying to get women used to being oppressed under Islam?"
"Did you know that the majority of black deaths are caused by other blacks?" the second tweet said. "Fix problems within your own community first before blaming others."
The tweets were sent in 2017 and 2018, but have since been deleted.
Zhu pushed back in a Twitter video Friday, claiming discrimination against her conservative political views. "Little attacks like those really, really diminishes the value and the trust of the word, 'racism,'" she said.
Zhu is a University of Michigan student, majoring in political science. She is an avid Donald Trump supporter on social media and the vice president of the College Republicans group at her school.
She will no longer go on to represent Michigan in the Miss World America pageant in Las Vegas.
Despite the backlash, Zhu said she stands by her old tweets. "I am glad this story came to light because this is more than just some beauty pageant, this is about the prejudice views against people with 'different opinions,'" she tweeted Friday.