As California has become more liberal in recent decades, and especially after President Trump was elected, gun control is one of several issues — along with climate change, immigration and health care — that have placed the state firmly in opposition to the federal government. In the wake of mass killings, the state’s political leaders often find themselves pushing for more gun control within California while speaking out against the federal government’s unwillingness to take up the issue, and against the National Rifle Association’s positions.

“The National Rifle Association — I’ll say this — is bankrupt, morally, and they need to be held to account to their rhetoric and their actions,” Mr. Newsom said.

He said of his own state: “California will do its job. I have all the confidence in the world. We have an extraordinary Legislature; they get it. They’ve gotten a lot done on gun safety, and they’ve got a governor who wants to raise the bar.”

Kevin de León, the former Democratic State Senate leader who on Tuesday lost his bid for the United States Senate to the incumbent, Dianne Feinstein, wrote on Twitter this week: “Congress’s great shame is their willingness to give the N.R.A. an outsized voice on how we enact gun safety. We will keep marching, legislating, advocating, and pushing Congress until they finally deliver gun safety laws that will keep our communities protected.”

Mr. Newsom did not this week offer specific new measures that he would push for, but he did say that he would have signed some gun control bills that Gov. Jerry Brown had vetoed in recent years. Among those were bills that would have expanded restraining orders, to allow co-workers, school employees and mental health providers to ask courts to take away guns from someone.

Even with the country’s toughest gun laws, California has still had the most deaths from mass shootings since 1982, according to a database compiled by Mother Jones — 128 people killed. Florida, with roughly half the population of California, has the second most deaths from mass shootings over that time, 118 killed.