Former Vice President Joe Biden on Wednesday unveiled his gun violence plan, just hours before a forum in which he and nine other Democratic presidential candidates will discuss what they plan to do about the issue.

Biden’s plan is not as ambitious as that of other candidates in the race, but it would still amount to the largest changes to America’s gun laws in more than two decades. It includes universal background checks, an assault weapons ban, more resources toward the enforcement of existing laws, a public push for the development of “smart guns,” and incentives for states to adopt “red flag” laws, which allow courts to confiscate guns from people deemed a risk to themselves or others and develop gun-licensing systems.

As part of the plan, Biden boasts that he has “taken on the National Rifle Association (NRA) on the national stage and won — twice.” As a senator in 1993, Biden helped pass the federal background checks law that still stands today. The year after, the now-controversial crime bill Biden helped write included a 10-year assault weapons ban.

“It’s within our grasp to end our gun violence epidemic and respect the Second Amendment, which is limited,” Biden’s campaign said. “As president, Biden will pursue constitutional, common-sense gun safety policies.”

As mass shootings like El Paso, Texas, and Dayton, Ohio, have received more attention, gun violence and policy have become more central to the 2020 campaigns. Before the debates, Democratic survey respondents said gun violence is a top issue they want to hear about. There were nearly 40,000 gun deaths in the US in 2017 — a 50-year high.

Biden’s plan, however, doesn’t go as far as other campaigns’ proposals. Cory Booker and Elizabeth Warren, for example, have proposed a federal licensing system — one that would require everyone in the US to obtain a license to buy and own firearms. But Biden’s proposal only includes financial incentives for states to adopt licensing, which they could decline to do.

In the past, Biden has criticized the concept of licensing, saying it “will not change whether or not people buy what weapons — what kinds of weapons they can buy, where they can use them, how they can store them.” The research has found licensing is among the more effective proposals for reducing gun deaths, more so than universal background checks or an assault weapons ban.

Biden’s plan also doesn’t include, as Booker and Beto O’Rourke have called for, a mandatory buyback program — essentially, a confiscation scheme — for assault weapons. Instead, his plan has a voluntary buyback program through which gun owners can sell assault weapons. But if gun owners don’t sell their assault weapons, they’ll have to go through a background check and register the weapons, just like they’re already forced to do so with machine guns today.

The proposal includes other ideas. It would close several loopholes in existing law. It would repeal a law that made it harder to sue gun manufacturers and sellers when they make or sell guns they should have known would be diverted to criminal uses. It would limit the number of guns an individual can purchase to one per month. It would require safe storage. It would finance strategies to combat urban violence in particular. It would fund more research into preventing gun violence. (For more specifics, read Biden’s full plan.)

Tougher gun laws are backed by the research. A 2016 review of 130 studies in 10 countries, published in Epidemiologic Reviews, found that new legal restrictions on owning and purchasing guns tended to be followed by a drop in gun violence — a strong indicator that restricting access to guns can save lives.

The question, even for Biden’s plan, is how likely any of this is to pass. Even though many of the proposals are popular among both Democrats and Republicans, the reality is Congress hasn’t moved even on universal background checks — an idea that, based on the polls, 80-plus percent of Americans support. In fact, Congress hasn’t passed a major gun control law since the measures in 1993 and 1994 that Biden boasted about in his plan.

Perhaps that’s why Biden is taking the more moderate route, declining to support a federal licensing system or a mandatory buyback program. But it’s unclear if even a moderate plan would pass — and research indicates it might not do much to actually reduce gun violence, anyway.

Biden’s plan shows a little movement on the issue of guns, but not much

In 1993 and 1994, a Democratic-controlled Congress passed federal background checks and a 10-year assault weapons ban. In the 25 years since, the debate has largely been relegated to … more background checks and an assault weapons ban. As the party has moved left on everything from single-payer health care to the Green New Deal to taxes on the wealthy, it hasn’t really moved on guns.

Biden’s proposal includes a little movement — calling, in particular, for states to adopt “red flag” laws and licensing systems. But the main pieces of his plan, especially since he stops short of calling for a federal licensing system, are still universal background checks and an assault weapons ban.

The research suggests that this isn’t enough. Some of the recent research on universal background checks has been mixed, and studies on the last assault weapons ban found it ineffective for reducing overall levels of gun violence, in part because the great majority of gun deaths involve handguns not assault weapons. But studies on licensing have been very consistent in significantly reducing gun deaths — in urban counties, Connecticut, and Missouri, including for suicides.

A federal licensing system, then, would likely have a bigger impact than the Democratic gun control mainstays.

Even then, a licensing system alone wouldn’t get the US down to the levels of gun violence seen in other developed nations. America leads the developed world in gun violence, with gun death rates nearly four times that of Switzerland, five times that of Canada, 35 times that of the United Kingdom, and 53 times that of Japan.

That’s because America’s problem is that it simply has too many guns. The US has far more guns than any other country in the world — more guns than people, according to the Small Arms Survey. That makes it easy to get a firearm, legally or not, leading to more gun deaths.

Research compiled by the Harvard School of Public Health’s Injury Control Research Center backs this up: After controlling for variables, such as socioeconomic factors and other crime, places with more guns have more gun deaths — not just homicides but also suicides, domestic violence, violence against police, and mass shootings.

Another way to look at this: Everywhere in the world, people get into arguments. Every country has residents who are dangerous to themselves or others because of mental illness. Every country has bigots and extremists. But in America, it’s uniquely easy for a person to obtain a gun, letting otherwise tense but nonlethal conflicts escalate into deadly violence.

Even the boldest Democratic proposals won’t do much to significantly reduce the number of guns in the US, at least in the short or medium term. (Any restrictions could, of course, reduce the number of gun owners over the long term.) Quicker action would likely require wider bans on firearms — potentially all semiautomatic weapons or all handguns — and coupling that with an Australian-style mandatory buyback program, which studies support.

But no Democrat is going that far. That reflects the political reality, given that Congress so far hasn’t taken up even the milder gun control proposals. And Democrats worry courts would just strike down tougher laws or that stronger measures could lead to a backlash that gets Democrats kicked out of office, like the 1994 assault weapons ban is blamed for.

Yet as long as all of that remains true, there will be little voice on the presidential stage to the kinds of policies that could get American gun violence down to the levels of the US’s developed peers.

For more on the Democratic presidential candidates’ gun proposals, read Vox’s explainer.