Former Texas Rep. Beto O'Rourke called for multiple gun control measures and steps to combat climate change in his first California appearance as a candidate for the 2020 Democratic presidential nomination.

Introduced Saturday by Los Angeles City Councilwoman Monica Rodriguez, who had campaigned for him in Texas in his unsuccessful bid for the U.S. Senate in 2018, O'Rourke took the stage at Los Angeles Trade-Technical College near downtown Los Angeles accompanied by a recording of the 1977 Queen song "We Will Rock You."

Following his introductory remarks, O'Rourke addressed Saturday's fatal shooting at a Poway synagogue, sending "our thoughts and our prayers and our wishes" to the victims of that and other shootings, "but I hope that I speak for everyone in saying I hope we will back that up with our actions to make sure that in this country, that sees more than 30,000 gun deaths every year, a rate not seen anywhere else in the world, that we will insist on universal background checks for everyone without loopholes or exceptions."

"We will also insist and ensure that weapons that were designed and sold to (the) United States military for the express purpose of killing people, as efficiently, as effectively and in as great a number as possible are kept on the battlefields and are no longer sold into our communities and they will end up in our synagogues, in our churches, in our mosques, in our public places," O'Rourke said to applause from the crowd.

Before his speech, O'Rourke tweeted that he was "heartbroken by the gun violence at Chabad of Poway synagogue on the last day of Passover. I stand with our Jewish neighbors and their freedom to practice their faith without fear. We must act now to end this hatred and gun violence. May the memories of those lost be a blessing."

The suspect in the Poway synagogue shooting used an AR-type assault rifle, authorities said. Its possession in California is limited to active members of the military permanently stationed in the state who have express permission from their base commander for use in military sanctioned activities only.

There is no indication the 19-year-old suspect was a member of the military.

According to figures released in December by the Centers for Disease Control and Prevention, there were 39,773 gun deaths in the nation in 2017 -- 23,854 ruled as suicides and 14,542 as homicides.

The others were the result of "legal intervention/operations of war" (553); unintentional (486) or undetermined (338).

The 46-year-old O'Rourke called climate change "the mother of all challenges."

Scientists "say there are still 10 years left to us, to free ourselves from a dependence on fossil fuels, to transition to renewable energy,... to do everything we can to set the example for the world and once again take our rightful role as the indispensable country, convening the other powers on this planet, together to do what otherwise is impossible, to keep us warming from another two or three degrees and ending life as we know it in some many parts of this country and of this world," O'Rourke said.

Many Republican officials believe the threat is exaggerated and proposals from Democrats offered as solutions would wreck the economy.

In an approximately 18-minute speech, including portions in Spanish, O'Rourke also called for "freeing every 'Dreamer' from any fear of deportation by making them U.S. citizens," referring to the young immigrants in the country illegally who were brought here as children.

The term is based on never-passed proposals in Congress called the DREAM Act.

Opponents say the law rewards people for breaking the law, encourages illegal immigration and hurts American workers.

O'Rourke arrived in California Saturday after speaking earlier in the day in Las Vegas at the National Forum on Wages and Working People sponsored by organized labor. He also campaigned in the early voting state of Nevada on Thursday and Friday.

O'Rourke is set to speak in San Francisco today, in Modesto on Monday and in San Diego on Tuesday.

O'Rourke was a three-term congressman from the El Paso area who gained nationwide prominence for his unsuccessful challenge of Sen. Ted Cruz, R-Texas, in 2018, receiving more votes than any Democrat in Texas.

"Beto O'Rourke's biggest accomplishment is naming a courthouse," said Christiana Purves, a regional communications director with the Republican National Committee.

"Add that to California Democrats' current struggle with overseeing basic tasks like providing Californians with identification and securing their voter information, and you have a glimpse of the train wreck an O'Rourke presidency would entail."

Born Robert Francis O'Rourke on Sept. 26, 1972, in El Paso, O'Rourke's Irish American family gave him the nickname "Beto" while he was an infant, initially to distinguish him from his grandfather, Robert V. Williams.

Beto is a common Spanish nickname for first names ending in "berto."

O'Rourke receivled a bachelor's degree from Columbia University in 1995, majoring in English literature.

O'Rourke began his political career in 2005, when he defeated a two-term incumbent to win a seat on the El Paso City Council.

He served on the council through 2011.

O'Rourke defeated eight-term incumbent Rep. Silvestre Reyes in a primary in 2012 and won the general election race in the predominantly Democratic district by more than 30 percentage points.

If elected, O'Rourke would be the first president born in the 1970s and the second Roman Catholic, after John F. Kennedy.