By Adam Winkler

When President Obama announced he would not endorse any candidate who doesn’t support stricter gun laws, it was another marker in a sea change in the discourse over guns in America.

Even in the absence of significant new federal legislation, the gun debate has been transformed since Newtown—and Aurora. And Tucson. And San Bernardino. And . . . the list goes on, tragically. Mass shootings have brought so much public attention to gun violence that the conversation has changed radically.

How? For many years before the Newtown shooting in December 2012, Democrats avoided talking about new restrictions on guns for fear of losing votes. As a candidate Obama downplayed gun control and emphasized his support of the Second Amendment. Now the Democratic presidential contenders are making gun control central to their platforms.

But does this new conversation mean that we are on the verge of meaningful change in America’s approach to guns?

There are hopeful signs. The gun control movement has been reinvigorated. Although Congress is stalled (on guns, along with a lot else), a significant percentage of the population lives in states that have enacted restrictive new gun laws: Colorado, Washington, Oregon, Maryland, California, Connecticut, Delaware, New Jersey, and New York among them. While the National Rifle Association has dominated campaign spending on gun issues for decades, there’s a more level playing field now largely due to former New York Mayor Michael Bloomberg’s money and former Rep. Gabrielle Giffords’ Super PAC. Polling shows widespread support, even among gun owners and NRA members, for reforms like universal background checks and banning people on terrorist watch lists from buying guns.

The country’s growing diversity is a challenge for the NRA. Gun ownership remains disproportionately concentrated among America’s declining demographics: white, rural, non-college educated. The country is becoming more urbanized and college-educated—groups strongly supportive of gun control.

Ironically, the gun control’s movement’s gains have come on the heels of its most devastating loss: the 2008 U.S. Supreme Court decision announcing that, as the NRA claimed, the Second Amendment guarantees an individual right to bear arms. The decision sparked hundreds of legal challenges to gun control laws. Yet the lower courts have upheld all but a handful of gun laws and the Supreme Court has shown little interest since Newtown in deciding another Second Amendment case. This term, the justices agreed to hear a case involving a gun law—and specifically directed the advocates not to argue about the Second Amendment.

But for all the momentum, gun control has political and public relations problems. The NRA still has a very strong hold on Congress. Support for the idea of gun control generally is at historic lows (even as support for specific proposals is high). And so as many states have loosened their gun laws since Newtown as have strengthened them. Many of these laws are minor, but that’s only because the NRA has been so successful that pro-gun advocates are left to push for guns in the few remaining places they aren’t allowed: college campuses, bars, and kindergarten classrooms.

Besides the NRA, control advocates are often their own worst enemies. There are effective gun reforms worth adopting: universal background checks, better reporting of criminal and mental health data into the federal background check database, cracking down on rogue gun dealers. Yet advocates also push for predictably ineffective laws like bans on military-style rifles, which, contrary to common belief, are not machine guns and are rarely used in crime.

The 2016 elections could be pivotal for gun control. With more mass shootings undoubtedly to come, don’t be surprised if the election turns out to be a referendum on guns. If Democrats lose the White House, in an election they are widely predicted to win, gun control will be blamed and likely become once again the hidden stepchild of the Democratic Party platform. A Republican president, by contrast, could enact new—and looser—gun laws, like national legislation broadening the right to carry guns in public.

Gun control advocates have hope and significant political momentum. But they have much, much more to lose this election than they can hope to gain.

Adam Winkler is a professor at UCLA School of Law and the author of “Gunfight: The Battle over the Right to Bear Arms in America”. He wrote this for Zocalo Public Square.