President Obama tonight sharply criticized the field of Republican presidential candidates for remaining silent after the booing of a gay soldier by members of the audience at the most recent GOP presidential debate.

“We don’t believe in the kind of smallness that says it’s OK for a stage full of political leaders — one of whom could end up being the President of the United States — being silent when an American soldier is booed,” Obama told a cheering crowd of gay and lesbian advocates at the annual Human Rights Campaign gala in Washington, D.C. “We don’t believe in that. We don’t believe in standing silent when that happens.”

Then, Obama spoke directly to his would-be opponents.

“You want to be commander-in-chief? You can start by standing up for the men and women who wear the uniform of the United States, even when it’s not politically convenient,” he said.

The comments are Obama’s first publicly on the incident, which occurred at the Fox News-Google debate in Orlando on Sept. 22.

When a gay soldier serving in Iraq asked a question of the candidates via YouTube, several members of the audience booed loudly. None of the candidates acknowledged the boos. Several said after the debate that they regretted not speaking up or could not hear the response from the stage.

Democrats have seized on the incident to portray the Republican field as out of touch and extreme. Vice President Joe Biden last week called the lack of response from Republicans on the stage “reprehensible.”