Also hitting back is Bono's mother, Cher, who gave birth to then-Chastity Bono 42 years ago.
The singer has defended her son on Twitter, saying "it took guts" to participate in the celebrity ballroom dancing show.
"Chaz is being viciously attacked on blogs and message boards about being on DWTS!" she wrote.
She urged her 340,000 followers to pledge their support for Bono on other social media sites.
"I support him no matter what he chooses 2do," Cher tweeted. "It took courage to do DWTS!"
She added that "mothers don't stop getting angry with stupid bigots" who hurt their children, but said she was sure the "vast majority of people will love Chaz" on the show.
Bono replied to the comments on his Twitter page saying: "Thanks for all your support mom. The haters are just motivating me to work harder and stay on DWTS as long as I possibly can."
So far, Bono's celebrity competitors on the show are sticking behind him as well.
"Unless Chaz commits a felony, I don't have a problem," HLN legal analyst and talk show host Nancy Grace told ABC News. ""I just don't think it's our business to be judging other people for their personal decisions. "
"I met Chaz, he's an absolutely lovely person and I'm just waiting to see how he dances," she added.
Besides Bono, Kressley and Grace, the Season 13 cast includes basketball star Ron Artest; World Cup soccer player Hope Solo; reality stars Robert Kardashian and Kristin Cavallari; TV personality Ricki Lake; singer-actress Chynna Phillips; actors David Arquette and J.R. Martinez; and Italian actress Elisabetta Canalis, better known in the United States as George Clooney's ex-girlfriend.
The man responsible for including Bono in that celebrity lineup, "Dancing With the Stars" executive producer Conrad Green, hopes the voting public will put their personal opinions aside and let Bono's dance moves do the talking.
"We think Chaz is a great guy with a really interesting story," Green told ABC. "One of the great strengths of our show is your ability to have preconceived ideas about people, but when you actually see them in the show, you might well end up with a different opinion of them."
The first test to see whether America is ready to accept a transgender dancing celebrity will come Tuesday, Sep. 20, when the couple with the lowest combined judges' scores and public votes for their performance will be sent home in the "Dancing with the Stars: The Results Show," at 9 p.m. ET.
"All I can do is share my experience, strength and hope," Bono said. "That's all I'm trying to do."
Watch the two-hour season premiere, Monday, Sept. 19 at 8 p.m. ET and visit abc.com for more information on "Dancing With the Stars" Season 13.