Levine, a Southern California Democrat who is sponsoring legislation to protect gay students from discrimination, welcomed the 100 teenagers to "their prom."
Held at Anthony's Steakhouse, the event mirrored a similar dance held in Hayward that until Thursday night was the only one of its kind in Northern California.
Hayward's event is sponsored by the Lambda Youth Project. Called the Gay Prom, it's now in its 12th year and draws 500 Bay Area lesbian, gay, bisexual, transgendered, questioning and straight young people under 20 years old.
Tracy's prom, much like Hayward's, "does not intimidate students from expressing who they are," said Justin Daley, 18, the prom's organizer and president of West High School's Gay/Straight Alliance Club.
Gay students in Tracy are allowed to attend high school proms that the school district officially sanctions with dates of the same sex, but some do not feel comfortable doing so.
Daley stressed that his event was inclusive and intended for students of any gender or sexual orientation.
Many of those who chose to attend did so to show support.
Kayla Lawhon, 14, of Manteca, said, "I've always been against any kind of hate. ... This is something I really believe in.
Margaret Lord, 17, also of Manteca, was there because she had a number of gay friends and had been a member of East Union High School's Gay/Straight Alliance Club for three years.
Muriel Gordon, 17, of Tracy said, "I thought this prom would be more fun."
The dance attracted kids from all over California, including one young woman from Long Beach.
Aya, 16, who did not wish to give her last name, said, "I'm gay and I'm proud. I'm not afraid of picket signs outside."
She need not have worried. Though the threat of anti-gay protesters loomed, none showed up.
Representatives from several gay advocacy groups were there acting as chaperones to make sure protesters did not block students from entering the building.
Part of the reason for concern dated back to last summer, when Daley's formation of the Gay/Straight Alliance Club at West High galvanized the Westboro Baptist Church of Topeka, Kan.
Westboro members threatened to return to protest the prom, but were no-shows.
That left some advocacy members free to boogie.
Judy Deane, 57, of Manteca said, "We're here to support and chaperone. Plus, we get to go to prom."
She was with her partner of 17 years, Ann Mollica, 43, also of Manteca. Both are members of Equality California.
Mollica was especially excited to be attending Tracy's gay prom.
"We can wear what we want to wear," she said. The two were dressed in tuxedos.
Aaron Swarts and Michelle Meyers contributed to this report.