WATCH: Beto O’Rourke joins protestors outside NRA convention days after mass shooting

HOUSTON (AP) — The National Rifle Association’s chief executive kicked off the group’s annual convention in Houston on Friday vigorously defending the rights of gun owners three days after a gunman killed 19 students and two teachers at an elementary school on the other side of the state.

Watch Biden’s remarks in the player above.

Former President Donald Trump and other Republican leaders are lined up to speak later at the event. Hundreds of protesters angry about gun violence demonstrated outside, including some holding crosses with photos of the shooting victims.

With the protesters, Democrat Beto O’Rourke, who is challenging Texas Gov. Greg Abbott in the governor’s race, ticked off a list of previous school shootings and called on those attending the convention to “join us to make sure that this no longer happens in this country.”

“The time to have stopped Uvalde was right after Sandy Hook,” O’Rourke said. “The time for us to have stopped Uvalde was right after Parkland. The time for us to have stopped Uvalde was right after Santa Fe High School. The time for us to stop the next mass shooting in this country is right now, right here, today with every single one of us.”

Some scheduled speakers and performers backed out of the event, including several Texas lawmakers and “American Pie” singer Don McLean, who said “it would be disrespectful” to go ahead with his act after the country’s latest mass shooting.

Colvin reported from New York. Associated Press writer David A. Lieb contributed from Jefferson City, Missouri.