Democratic presidential candidate Martin O'Malley wanted to make one point clear in the first Democratic debate: He is not afraid to stand up to the National Rifle Association and push for stricter gun laws. Asked which political enemy he's the most proud of, O'Malley said, "The National. Rifle. Association."

O'Malley is not bluffing about his reputation with the NRA. The group gave him an F on gun rights when he ran for governor in 2010. As governor of Maryland, he also signed some of the strictest gun laws in the country, further earning the NRA's ire. And when the NRA called him a "menace," he wrote a column stating, "I've never given in to the NRA, and I certainly won't as president. I believe that we shouldn't be taking gun safety advice from groups that only exist to sell more guns."

O'Malley has also come out with what is arguably the most detailed and aggressive gun control plan of any of the Democratic presidential candidates. And he linked the plan to a very ambitious goal: to cut US gun violence deaths by half in 10 years.

But as aggressive as his proposal is, it runs into two big problems: It almost certainly couldn't get through Congress. And even if it did, it would fall far short of solving America's very unique gun problem — because not even Democrats are asking to go far enough to reform gun control.

O'Malley has the most ambitious gun proposal. But does it matter?

The debate over gun control has been thrust into the national spotlight following recent school shootings, which have once again forced Americans to confront levels of gun violence that no other developed country has to deal with. The US has nearly six times the number of gun homicides as Canada, more than seven times as Sweden, and nearly 16 times as Germany.

O'Malley, long an enemy of the NRA, has put this issue at the center of his campaign.

To understand O'Malley's ambitious gun control proposal, it's important to first know what his major rivals support. Bernie Sanders is supportive of modest gun control measures: expanding background checks, a ban on high-capacity ammunition magazines carrying more than 10 rounds, and a ban on assault weapons. Hillary Clinton wants to go a bit further, vowing to expand background checks through executive actions and to repeal limits on lawsuits against gunmakers and dealers.

O'Malley essentially takes all of these ideas and adds new policies: an age requirement for handgun ownership (21 and older), fingerprint licensing, increased enforcement of laws that block stalkers and domestic abusers from owning guns, and much more.

One of O'Malley's more interesting ideas is to use the federal government's purchasing power — as the largest buyer of firearms in the country — to encourage gunmakers to include hidden serial numbers, microstamping, and other design changes that would make it easier to trace guns. This wouldn't necessarily prevent gun violence, but it's a pretty unique idea, and it would make it easier to go after criminals.

But as ambitious as O'Malley's proposals are, they will very likely never make it through Congress. Democrats have some chance of taking the Senate in 2016, but the chances that Democrats will take the House in 2016 are practically nonexistent. And a Republican-controlled House will almost certainly not let stricter gun laws pass.

Even O'Malley's proposal likely won't bring gun violence down to other developed nations' levels

Even if, miraculously, O'Malley, Sanders, Clinton, or — now we're talking real miracles — Lincoln Chafee got his or her gun control plan through Congress, none of their plans are likely to bring US gun violence down to other developed nations' levels.

The empirical research on guns has consistently found one correlation: More guns lead to more gun deaths. This means that reducing access to guns — and perhaps cutting the number of firearms through attrition — would likely have a small effect on firearm deaths over time. But to significantly and quickly cut gun deaths, America would need to immediately reduce the number of guns.

This is essentially what Australia did after 35 people died and 23 were wounded in the Port Arthur massacre in 1996. Through a mandatory buyback program, it seized and destroyed more than 650,000 firearms — as much as 20 percent of the nation's stock, by some estimates. One study of the program, by Australian researchers, found that buying back 3,500 guns per 100,000 people correlated with up to a 50 percent drop in firearm homicides and a 74 percent drop in gun suicides. The drop in homicides isn't statistically significant, but the decline in suicides was.

As Vox's Dylan Matthews wrote, a similar program would be required to quickly cut gun violence in the US. Less drastic measures — like those proposed by O'Malley and Clinton — could help, especially over time, but the research suggests they wouldn't be enough to bring US levels of gun violence down to European levels.

Still, if you consider gun violence a top problem, O'Malley's plan certainly suggests he would go further as president to address the issue than any other candidate. But the reality is America's gun problem is so uniquely bad that it will likely require much more drastic measures than anyone is proposing.

Watch: America's biggest gun problem is rarely talked about