Prior to shooting former Congresswoman and current Americans for Responsible Solutions co-founder Gabby Giffords and 18 others at a supermarket in Tucson in January 2011, Jared Loughner photographed his United States history textbook with a handgun lying on top of it. "You don't have to accept the federalist laws," he stated in his political manifesto on MySpace. His writings and posts painted a picture of a man deeply dissatisfied with government and determined to act. The resulting massacre claimed six lives and left Giffords and others catastrophically injured.

Now, five years later, insurrectionist violence continues to plague our nation. The mass shootings in Dallas and Baton Rouge targeting law enforcement officers are merely the most recent examples of armed attacks against our democratic government.

In my 2009 book, Guns, Democracy and the Insurrectionist Idea, co-author Casey Anderson and I argued that the seeds of violence against our government have been sown and watered by the gun lobby and the GOP. We cannot look away from these latest shootings and say, "We never saw this coming." The National Rifle Association's dangerous philosophy--that the Second Amendment guarantees an individual right to commit acts of violence against government officials--has been inspiring acts of political violence for at least two decades. It is an idea embraced by both prominent conservative leaders and mass shooters, and it threatens to lead our nation to anarchy.

My organization has been tracking insurrectionist violence since the 2008 D.C. v. Heller Supreme Court ruling, when the late Justice Antonin Scalia, writing for a 5-4 majority, mused that the Second Amendment was ratified to "assure the existence of a 'citizens' militia' as a safeguard against tyranny." The NRA has used high-profile Republicans like Newt Gingrich to reinforce this point . At the organization's 2010 annual meeting, Gingrich told NRA members:

The right to bear arms is not about hunting. It's not about target practice. The right to bear arms is a political right designed to safeguard freedom so that no government can take away from you the rights that God has given you, and it was written by people who had spent their lifetime fighting the greatest empire in the world, and they knew that if they had not had the right to bear arms they would have been enslaved.

In recent years, the militia movement and other right wing groups have internalized and acted on this insurrectionist philosophy. In 2014, we narrowly escaped a bloodbath in Bunkerville, Nevada during the siege of the Cliven Bundy ranch. Two individuals who had spent time protesting at the ranch with Bundy ended up killing two police officers in cold blood at a pizza restaurant in Las Vegas. The couple covered one of the officers with a yellow Gadsden flag and a swastika. They pinned a note on the other officer which read, "This is the beginning of the revolution."

In 2015, the Oath Keepers forcefully took over the Sugar Pine Mine in Oregon. Then, in January, the Bundy family once against rebelled, taking over the federal Malheur National Wildlife Refuge with a small militia.

Many viewed these rebellions as the isolated political statements of a few fringe actors rather than the legitimate threat to democracy they are. The insurrectionists were mocked and called "y'all-Qaeda" and "yee-haw-dists." Few made the connection between their violence and the NRA and GOP's dangerous rhetoric. To this day, there has not been any high-level discussion among lawmakers about the threat of insurrectionist violence. In fact, Republicans have taken pains to discredit such conversation. For example, many Republican members of Congress suggested that a 2009 Department of Homeland Security report about the threat of homegrown terrorism was a conspiracy theory .

Sadly, prominent members of the GOP have continued to promote insurrectionist ideology. In a fundraising email last year, Senator Ted Cruz, who has become a mainstream voice in the Republican party, said , "The Second Amendment...is a Constitutional right to protect your children, your family, your home, our lives, and to serve as the ultimate check against governmental tyranny--for the protection of liberty."

We can only hope that the GOP will change its tune in the wake of mass shootings targeting police officers in Dallas and Baton Rouge.

Both the Dallas shooter and the Baton Rouge shooter were troubled men who became angry, as many of us did, after watching videos of police officers killing Alton Sterling and Philando Castile. Instead of seeking peaceful redress, they decided to retaliate with violence--to exercise their supposed individual right to combat government tyranny.

Both men benefited from policies advanced by the NRA and GOP. The Dallas gunman was armed with an SKS semiautomatic rifle and a handgun equipped with high-capacity ammunition magazines. He blended in at the rally because of Texas open carry laws, which allow citizens to carry long guns with no permit, background check, or training. Dallas Mayor Mike Rawlings indicated that approximately 20 others were openly carrying long guns at the event, some wearing gas masks and/or body armor. Police apprehended multiple suspects because they were unsure which individuals with rifles were shooters.

Prior to the Baton Rouge massacre, the shooter, a self-proclaimed "sovereign citizen ," walked down Airline Highway toting an assault rifle. Like Texas, Louisiana allows citizens to openly carry firearms with no screening whatsoever . The Baton Rouge gunman was behaving perfectly lawfully by strolling down the street with a loaded AR-15 --right up until the moment he opened fire on law enforcement.

An America in which extremists are encouraged to resolve disputes by lethal force--and abetted in their pursuit of firepower by the gun lobby--is not the America our Founders envisioned. The toxic mixture of hate and unchecked proliferation of firearms is now actively undermining our democratic institutions and key freedoms. We have allowed the NRA to run roughshod over the basic tenet established in our Constitution: to "insure domestic Tranquility" by redressing our grievances through the myriad peaceful avenues defined in that document.

The modern GOP has endorsed a culture in which dissatisfaction is justification for murder. If this is truly what they believe, they must answer to the families of those slaughtered by armed insurrectionists. If it is not, they must swallow their pride, denounce insurrectionism, and make a determined effort to de-escalate the violence we are seeing before it is too late.