As one of the most influential right-wing activists in the United States, Charlie Kirk shaped much of the hard-right youth movement on key political issues.

Mr. Kirk founded Turning Point USA, a political organization designed to rally young conservatives. He was answering questions about transgender politics and mass shootings from students at Utah Valley University on Wednesday when he was shot and killed. Authorities have not yet identified a suspect and said the investigation was ongoing.

Here are some of the issues Mr. Kirk focused on and where he stood:

Gun Control

Mr. Kirk was a strong supporter of gun rights.

At a 2023 event by TPUSA Faith, a division of Turning Point USA, he defended the Second Amendment as a critical means to “defend yourself against a tyrannical government.” He said it would be impossible to avoid gun deaths in a society with an armed citizenry, but he believed the benefits of gun rights outweighed the costs.

“I think it’s worth to have a cost of, unfortunately, some gun deaths every single year so that we can have the Second Amendment to protect our other God-given rights,” he said.

Mr. Kirk said the way to reduce gun violence was simple: Put guns into the hands of more Americans.

“If our money and our sporting events and our airplanes have armed guards, why don’t our children?” he asked.

Gender Identity

Mr. Kirk appealed to conservative Christians who feared the growing acceptance of the L.G.B.T.Q. community in the United States. He was critical of gay and transgender rights and the separation of church and state.

He encouraged students and parents to report professors whom they suspected of embracing what some on the right refer to as gender ideology.

In 2021, he founded TPUSA Faith, which “exists to unite the church around primary doctrine and to eliminate wokeism from the American pulpit,” according to its website.

Immigration

Mr. Kirk supported Mr. Trump’s campaign against immigration, endorsing the so-called Great Replacement Theory, which claims that immigrants will soon displace white Americans. The unsubstantiated theory also claims that Jews are orchestrating the dilution of white power by allegedly encouraging mass immigration.

“Jewish communities have been pushing the exact kind of hatred against whites that they claim to want people to stop using against them,” he said on his podcast, “The Charlie Kirk Show,” in 2023.

Climate Change

Mr. Kirk frequently dismissed concerns about climate change, even as polling showed that young conservative voters prioritize the issue. He said incorrectly that there was no scientific consensus on global warming.

He also rejected the idea that climate change posed an existential threat to humanity, describing it as “complete gibberish, nonsense and balderdash” in December 2024 to members of Turning Point UK, the British offshoot of Turning Point USA.

Last month, Mr. Kirk’s podcast featured Energy Secretary Chris Wright, who has called global warming “not incredibly important.”