For years, Gov. Gavin Newsom has signed law after law layering on bans, restrictions and limitations on guns in California, only to see those laws swatted down by conservative judges for violating the U.S. Constitution’s right to keep and bear arms.

Now Newsom has a new idea: Change the Constitution itself.

Today the governor, who has become one of the country’s most outspoken advocates for tighter gun laws, proposed adding a 28th amendment to the U.S. Constitution to place new age limits, background check requirements and mandatory waiting periods for gun purchasers. His proposed amendment would also ban the civilian ownership of so-called assault weapons.

Most of these proposals come from California’s own lengthy list of gun laws. They’re popular here. But though Congress has yet to pass them, most public polling suggests they’re broadly popular ideas across the country.

Adding an extra amendment is extraordinarily difficult. But for Newsom, the proposal may be as much about political strategy as constitutional law.

“We want to go on the offense and be for something and build a movement that’s bottom up, not top down,” he told Politico in advance of his announcement.

Shortly after the news dropped, Newsom’s PAC, Campaign for Democracy, blasted out a text alert urging supporters to signal their support by sharing their name and contact information. Recipients were also invited to make a donation.

Here are five questions about Newsom’s latest proposal, answered.

What would the Newsom amendment actually do?

The governor’s office has yet to share the text of Newsom’s proposed addition to the Constitution. Democratic Assemblymember Reggie Jones-Sawyer plans to introduce the amendment in the California Legislature, but was no more forthcoming with details on Thursday.

But according to the governor, the amendment would add four specific firearm restrictions to the U.S. Constitution:

• Raise the federal minimum age for all gun buyers to 21. Federal rules already apply that higher limit to handgun purchasers, but 18-year-olds are allowed to buy rifles and shotguns.
• Require an as-yet-unspecified “reasonable waiting period” between the time a person pays for and receives a gun. California has a 10-day waiting period, though there is no nationwide policy.
• Require background checks for all gun purchases. Federal law already mandates this for sales from licensed firearm dealers, but not for non-professional vendors who might set up a stall at a gunshow or sell to a family member or friend. California already imposes mandatory background checks on all sales.
• Bar civilian purchase of assault weapons. California has such a ban in place, but as lawmakers here have discovered, coming up with a consistent, working definition of “assault weapon” is easier said than done.

In a press release touting the announcement, Newsom stressed his proposed constitutional change would leave “the Second Amendment unchanged.” But the governor’s proposed 28th amendment would also “affirm Congress, states, and local governments can enact additional common-sense gun safety regulations that save lives.”

Whether those two pledges contradict one another depends on how robust one believes the Second Amendment’s protections truly are.

Many gun safety rules described by their proponents as “common sense” have been found by courts to run afoul of the Constitution. After the Supreme Court struck down restrictions on concealed carry permits last year, applications surged in California — particularly in the state’s liberal-leaning counties.

What are the odds of this actually happening?

Not great.

Since the framers of the Constitution ratified the first 10 amendments in 1791, the document has been tweaked only 17 times. The last amendment was added 31 years ago.

Why so few? Because amending the Constitution is really hard.

Proposing an amendment requires the support of two-thirds of the U.S. House and Senate. Another, more bottom-up option: Two-thirds of state legislatures (34 out of 50) can propose the convening of a Constitutional Convention

Some context: Two-thirds of the Congress rarely agrees on anything, much less something as politically charged as gun control. As for the convention route, the notion of inscribing gun restrictions in the Constitution is likely to meet a chilly reception in the 28 statehouses currently held by the GOP. Plus, the convention method has never been used, so it’s not entirely clear what it would look like. Even so, Newsom appears to be pursuing the second strategy, which is why Jones-Sawyer plans to float the idea in the Assembly.

Jones-Sawyer said that, as part of their effort, lawmakers would reach out to other state legislatures where they had strong relationships and Newsom could speak with other governors to get this proposal on the agenda in other states — even those controlled by Republicans.

But whether proposed by Congress or convention, actually adding the next text to the Constitution faces an even higher barrier: The sign off of three-fourths of state legislatures (38 of 50), or three-quarters of state conventions called to consider the amendment.

Are these gun safety policies actually effective?

According to the RAND Gun Policy in America initiative, which gathers and summarizes research on the topic, some evidence suggests that all four of the policies proposed by Newsom would reduce gun violence, but in different ways.

Raising the age limit for gun buyers is associated with reduced rates of suicide. More expansive background checks coincided with overall reductions in violent crime. Longer waiting periods corresponded with both. And though the evidence on assault weapon bans is a bit weaker, some studies suggest they may reduce both the number of mass shootings and make those that do occur less deadly.

What about California’s own gun violence problem?

California has some of the strongest gun restrictions in the country. Its rate of gun deaths is also among the lowest.

But though Newsom may tout California as a national model on gun policy, the state has often struggled to implement the laws it already has on the books, a point underscored today by some of Newsom’s critics.

“This is just another political stunt from this governor who does this all the time to distract from his failures in California,” said Assembly Republican Leader James Gallagher of Chico.

Gallagher agreed that gun violence is a problem politicians need to address and that California’s background check laws had likely contributed to its lower rates of shootings, but he slammed Democrats for not prioritizing getting guns out of the hands of criminals.

For years, the state has maintained a list of gun owners who committed a felony or a violent misdemeanor and lost the legal right to possess a firearm. And for years, the state’s Department of Justice has struggled to bring that backlog of “armed and prohibited persons” down by seizing weapons from people on the list.

California also has an expanded “red flag” law that allows police officers, family members, romantic partners and roommates to ask a court to order firearms removed from someone if they’re believed to pose a threat to themselves or others. But law enforcement agencies have struggled to roll out these programs.

California legislators, the majority of whom favor tighter restrictions on firearms, are also scrambling to push back against a judiciary intent on empowering gun owners. Glendale Democratic Sen. Anthony Portantino wrote a bill that promises to reimpose some of the restrictions on concealed carry permits recently struck down by the Supreme Court. But it won’t become law before next year and is all but certain to face a legal challenge.

For some of Newsom’s allies, the impediment imposed by the courts makes changing the Constitution not just a necessary step to reduce gun violence across the country, but to protect the laws that California has already passed.

“With the radicalization of the Supreme Court having a detrimental impact on the public safety of all Americans as it systematically dismantles common sense gun legislation, we must look at a constitutional amendment to both ban assault weapons and to protect the sanctity of California’s ability to regulate firearms and keep our citizens safe,” said Portantino in a statement.

Is this just a political stunt?

Newsom has said over and over that he has no interest in running for president, while repeatedly doing things consistent with someone very interested in doing exactly that.

In recent years, the governor has enthusiastically elevated his national profile by picking fights with Republican governors, scolding his own party for failing to go on the offensive and touring red states. Add floating a base-riling constitutional amendment to the list.

But even if Newsom’s amendment isn’t likely to get ratified anytime soon, there’s still value in “injecting it into the public square,” said longtime Democratic political strategist Garry South.

“For nearly 50 years the anti-abortion crowd has been pushing for a constitutional amendment to ban abortion,” he said. “That was never going to happen, but they banged that drum for so long and so loudly that ultimately, the US Supreme Court overturned Roe v Wade.”

And even if Newsom’s proposal is just politics, it may be smart politics. Tighter gun restrictions may be a no-go in Congress, but they have broad popular appeal, even among some Republicans.

According to a Fox News national poll from this spring, more than three-fourths of respondents favor some version of the governor’s first three proposals: a 21-year age limit, universal background checks and a 30-day waiting period.

Another 61% support a national ban on assault weapons, the pollsters found.

Ben Christopher and Alexei Koseff are reporters with CalMatters.