“Donald Trump is the most pro-LGBT nominee that the party has ever had,” he said. “He just comes from a very different place on these issues. He has a stellar record when it comes to LGBT community issues.”

Some gay Republicans are less generous in assessing Mr. Trump’s record on their issues. The billionaire businessman has expressed varying degrees of opposition to same-sex marriage and waffled on the transgender bathroom issue.

Still, Mr. Trump impressed gay conservatives when he spoke forcefully about defending the gay community in the wake of the June 12 Islamist terror attack on the Pulse nightclub in Orlando, where 49 people were killed in the worst terror attack in the U.S. since 9/11.

“I refuse to allow America to become a place where gay people, Christian people, Jewish people are targets of persecution and intimation by radical Islamic preachers of hate and violence,” Mr. Trump said in the speech.

Mr. Barron said the message should resonate with gay voters and others who care about such issues.