Roughly 7,000 delegates Saturday ratified the platform without debating their party's stance on homosexuality on the convention floor. They instead argued for five hours over immigration and medical marijuana before adjourning.
Gay conservatives had lined up to speak against the therapy language that had been added earlier this week. But they never got a chance to address delegates because a parliamentary motion to approve the full platform was called first.
Texas Republicans have adopted a party platform that includes support for voluntary psychological "therapy" targeted at converting homosexuals to heterosexuals.
Almost 10,000 attendees gathered in Fort Worth at the annual Texas GOP Convention to vote on a platform ahead of the 2016 race for the White House.
Supporters of "conversion" or "reparative" therapy believe the treatment is effective in turning gays straight. California and New Jersey have banned the treatment for minors.
The Texas Republicans' measure states that "We recognize the legitimacy and efficacy of counseling, which offers reparative therapy and treatment for those patients seeking healing and wholeness from their homosexual lifestyle. No laws or executive orders shall be imposed to limit or restrict access to this type of therapy."
Spearheading the endorsement is Cathie Adams, president of the conservative Texas Eagle Forum. She stressed that the measure calls for allowing people to choose the treatment.
"Nothing is mandatory," Adams wrote in an e-mail to CNN on Saturday. "If a person chooses counseling, then it should be made available. California and New Jersey have passed bills OUTLAWING it altogether, which is under litigation. It's a freedom issue."
But an array of professional organizations oppose gay conversion therapy. Such groups include the American Medical Association, the American Psychiatric Association and the American Psychological Association.
"The most important fact about these 'therapies' is that they are based on a view of homosexuality that has been rejected by all the major mental health professions," said the APA, the nation's largest scientific and professional organization representing psychology.
"To date, there has been no scientifically adequate research to show that therapy aimed at changing sexual orientation ... is safe or effective."
Adams told CNN in a phone interview she was introduced to reparative treatment by a constituent in her precinct who claimed he was a gay man who is now straight because of such treatment.
"I do not think homosexuals are born as homosexuals," Adams said.
"To say this is an unchangeable thing, there are too many people who've changed their mind about homosexuality. No one can change the color of their skin or change the place they're born, but they can definitely choose their lifestyles," she added.
Last August, New Jersey Gov. Chris Christie signed into law a measure banning gay conversion therapy for minors.
"The American Psychological Association has found that efforts to change sexual orientations can pose critical health risks including, but not limited to, depression, substance abuse, social withdrawal, decreased self-esteem and suicidal thoughts," the Republican governor said in his signing statement.
"I believe that exposing children to these health risks without clear evidence of benefits that outweigh these serious risks is not appropriate."
