There have been a staggering number of mass shootings in the past few years, and the reaction to each from politicians has become appallingly familiar. There are the thoughts and prayers, the call for change, and then … nothing. And then it happens all over again.

Why doesn't anything change? And why do we only seem to talk about these policies after a massacre? Here's a look at what kinds of conversations America seems to have after shootings — and what kinds of questions get left behind.

What does the federal government even do after a mass shooting?

Policy-wise, not much. Congress last passed federal gun legislation after the Virginia Tech shooting in 2007 — which was, until this week, the deadliest mass shooting in U.S. history. The new law encouraged states to make sure that the background check system had access to states' mental health records. Five years later, in 2013, shortly after the mass shooting at Sandy Hook Elementary School in Connecticut, legislators tried to pass a law that would have made it so people who buy firearms online or at gun shows have to get a background check. At that point, Democrats still controlled the Senate, and a majority of Americans — regardless of political affiliation — said they liked this idea.

So why didn't it pass?

The bill still couldn't reach exit velocity thanks to an unhealthy fear of the impending 2014 midterms — and all the ads that conservative Democrats thought they would have to deal with if they voted for the background checks. Guess what: The National Rifle Association spent money against many of them anyway.

What are legislators saying now?

On Wednesday, Connecticut Senator Chris Murphy launched a filibuster, urging that Congress vote on a gun bill ASAP. He talked for nearly 15 hours, buoyed with questions or long speeches from his colleagues. “I think when there is not a collective condemnation with policy change from what is supposedly the world's greatest deliberative body," Murphy

target="_blank">argued, "that there are very quiet cues that are picked up by people who are contemplating the unthinkable in their mind.”

He only stopped talking when Republicans agreed to a vote. A background check bill similar to the one that failed three years ago will get another try, as will a few bills that are a more specific reaction to recent tragedies.

Since the Orlando shooter declared allegiance to ISIS during the attack and was twice investigated and cleared by the FBI, this most recent policy debate has mostly revolved around counterterrorism and repeating things like "strength" and "why aren't you saying radical Islam?" Although, as Masha Gessen argues in The New York Review of Books, focusing on vows to fight terrorist groups after actions made by individuals with very tenuous connections to said groups might backfire: "The message of the terrorist is, ‘I matter. My cause matters. My hatred matters. My ability to act matters.' We respond by saying, ‘Yes, you matter.’"

But what policies dealing with terrorism and guns have been discussed?

The specific policy discussion that has followed the Orlando shooting also deals with terrorism — namely whether those on the FBI's terror watch list should be able to purchase firearms. This isn't a new debate; Congress considered a bill that would have prohibited those on the no-fly list from purchasing firearms after the shooting in San Bernardino last December. It failed mostly along party lines, with Democrats now defending a list that they said was a civil liberties mess almost a decade ago.

Donald Trump says he is intrigued by this idea; his fellow Republicans (and the NRA) instead only want to delay gun purchases for those on the no-fly list by 72 hours.

The Senate will likely vote on bills that deal with the watch list in a number of ways, with various flavors derived from the wishes of each party. It's not clear that the majority of the body is ready to compromise on anything quite yet.

Wait, was the Orlando killer on the list?

It doesn't seem like this measure would have prevented the San Bernardino killers or the Orlando shooter from passing a background check — none of them appear to have been on the no-fly list or the terror watch list at the time of the attacks. Even if the proposal fails to gain traction this time around, the New York Times reports that "the Justice Department might look to adopt new procedures that would alert counterterrorism investigators if someone who had been on a terror watch list tried to buy a gun."

What about the gun used in the shooting?

There has also been talk about the weapon that allowed a man to murder dozens of people so quickly. The killer used an AR-15-style assault rifle — just like the shooters at San Bernardino, Newtown, and Aurora. The gun has been heavily marketed by manufacturers. President Obama said that we should ban assault weapons earlier this week. In Tennessee, State Representative Andy Holt did not revise his plan to give away an AR-15 door prize at a fundraiser later this month after the shooting. Holt, who sponsored recent legislation that has made carrying concealed weapons on college campuses legal in the state, told The Tennessean, "It has nothing to do with the style of weapon. It has everything to do with who’s behind the weapon."

Wouldn't background checks help?

Not in this specific instance. One of the realities of only debating federal gun policy after a mass shooting is that the parameters of the discussion are limited by the specific details of the attack. The Orlando shooter passed a background check, a fact that will probably cut short any discussion about this realm of gun law.

As you might imagine, only talking about measures that could stop one specific individual tends to make policy-making difficult.

On top of that, it's an election year; gun policies that can't pass in non-election years aren't going to find much support in the legislative no-man's land that is pre-November insanity.

What kind of things get ignored when we only talk about guns after a shooting?

It's definitely leading us to have a pretty limited debate about guns in America. "We shouldn’t make gun policies just to prevent mass shootings," Jon Vernick, codirector of the Johns Hopkins Center for Gun Policy and Research, told MTV News. He notes that there are around 33,000 gun deaths and 11,000 gun homicides a year in the U.S. — crimes that are much more responsive to the nuances of policy than the massive murderous events that are much better at captivating the nation’s attention. Gun suicides in particular deserve attention; although violent crime writ large has been decreasing steadily for decades, gun suicides are going up. The Harvard Injury Control Research Center has done studies that show that states with more guns have higher suicide rates.

Also, not every mass shooting in the U.S. gets massive national news coverage. According to the Gun Violence Archive, there have been 141 mass shootings in 2016. In most of these incidents, one or two people die from their wounds — enough to be horrible, but small enough to banish them to the background, where they join the tens of thousands of other deaths that just become a disquieting daily hum instead of something that punctures the national conscience.

That's depressing.

Regardless of what changes could be implemented, there will still be mass shootings. However, making fewer of them happen is possible — and the shootings legislators probably have the most power to affect are those we usually don't talk about as much.

Speaking of gun research, what do the people who actually study this stuff say we should do after shootings?

They probably mostly wish it was easier for them to do studies on incidents like this. The truth is that we don't have much data on gun violence in America. A tiny part of a law passed way back in the '90s is mostly responsible — it prohibited the Centers for Disease Control and Prevention from helping conduct any research that is used "to advocate or promote gun control.” That doesn't mean that the CDC can't give grants for gun-violence research, but it has made many researchers wary about getting close to the field, lest they be accused by the NRA of having anything to do with gun control efforts.

This information shortfall also makes responding to firearm deaths more difficult. You can contrast this with our response car crashes or smoking — public health researchers studied the deaths and gave suggestions for how to best alleviate the problems. It worked.

When politicians debate gun policy after mass shootings, one reason for not doing anything is often, "Well, we don't know if this policy would even help." Having actual data might make it easier to provide those answers.

What about individual states? Have they done anything in response to mass shootings?

Although you can sum up what has happened on the federal level with a series of big blanks punctuated by a few executive actions from President Obama, states have been far more active. (It's a bit easier to pass controversial policies when your state government is dominated by one party.) In the year after the Newtown shooting, the New York Times noted that 109 new gun laws were enacted. Thirty-nine measures tightened regulations; 70 loosened them.

By Mother Jones's count, 21 states, which contain more than half of all Americans, have passed tougher gun laws since Newtown — expanded background checks, assault weapons bans, laws that make would-be owners get a permit before they can purchase a handgun, etc. In other states — where legislators think the best response to violence is to make it easier to defend yourself with a gun — laws have passed that make it possible to openly carry weapons in public, or to carry concealed weapons on campuses and in legislative chambers.

State legislators definitely don't only talk about these policies immediately after a mass shooting, either. Take Florida, the scene of Sunday's shooting. Laura Cutilletta, managing attorney at the Law Center to Prevent Gun Violence, told MTV News that the Florida State Legislature considered at least 34 gun bills this year, although only two passed. Just last week, the state Supreme Court heard a case concerning the issue of whether people should be able to openly carry firearms.

How do gun owners fit into all of this?

Gun owners typically respond to mass shootings by buying lots of guns. A year after Newtown, Bloomberg reported that "in 2005 fewer than 9 million [background] checks were done. For the first 11 months of 2013, that figure rose to more than 19 million." In December, the New York Daily News reported that "the four biggest gun makers [had] cleared more than $632 million in profits" in the three years after Newtown. The jumps in sales usually happen after a jump in talk about gun policy — which by default means that they happen after mass shootings. One financial analyst told the New York Times, “President Obama has actually been the best salesman for firearms." A Huffington Post reporter went to a gun shop in Orlando to see how long it would take to buy an AR-15 (the answer is 38 minutes) and saw a picture of Obama on the wall that said the same thing: “Firearm Salesman of the Year."

In short, every time we talk about gun policy on the federal level, it hasn't resulted in any changes in law — but it has led to a steep increase in the number of guns. In the hours after the shooting in Orlando, gun stocks leapt in anticipation of all the weapons that would soon be bought.

And what about the whole country? Does public opinion about guns ever change after mass shootings?

The majority of Americans have said they are in favor of expanded background checks, assault weapons bans, and laws that keep guns away from the mentally ill. Ask the question more broadly, however, and you get a completely different answer. Over the past decade, an increasing number of Americans have said that it is more important to protect gun rights than control gun ownership, per the Pew Research Center.

So … they like gun restrictions, except when they don't?

The mixed signals on gun policy do a good job of mirroring the confusing debates we have about these shootings, don't they? The Roper Center for Public Opinion Research released a big report late last year that concluded, "Although high-profile incidents can increase support briefly, the cumulative effect of the increasing number of mass shootings does not appear to be higher support for restrictions on guns." The Roper study also showed that Americans seem to have become somewhat resigned to the status quo — both the number of shootings and the response to them: "After mass shooting incidents in recent years," the study notes, "up to two-thirds of the country have said that such shootings will happen again regardless of what action is taken."