The congressman from North Carolina brandished a gun as he addressed a Macon county Republican event last weekend. “We all need to be storing up some ammunition,” Madison Cawthorn warned the crowd, as he embraced the big lie about the 2020 presidential race and insisted that “we all know it was a stolen election”.

Then, chillingly, Cawthorn conjured a second civil war being fought over his fraudulent claims. “If our election systems continue to be rigged and continue to be stolen, then it’s going to lead to one place,” Cawthorn said, “and that’s bloodshed … As much as I am willing to defend our liberty at all costs, there’s nothing I would dread doing more than having to pick up arms against a fellow American.”

We awaken every day to pillars of liberal democracy torn down, wrecked norms and ruined institutions, fresh assaults on foundational freedoms from state legislatures and runaway courts, political leaders bathed in the hateful stew of rightwing media and racing to bend a knee before an authoritarian leader who himself bowed before dictators and cared so little for his voters that he offered them bleach during a pandemic.

The roots of this fearful moment run deep: a constitutional system unprepared for a political party willing to play constitutional hardball; a Democratic party that neglected local elections while Republicans invested in a decades-long effort to capture state legislatures and the courts; winner-takes-all districts that break toward extremes under severe polarization; a nation that has never been willing to embrace multiracial democracy.

But there’s a simpler reason that Cawthorn can spew such an abhorrent incitement to violence. His extremism was created intentionally by aggressive partisan gerrymandering. Cawthorn and many of the other demagogues and conspiracy theorists who have hijacked the Republican party owe their seats to the noncompetitive districts Republicans drew themselves a decade ago. Without gerrymandering, Cawthorn would just be another loudmouth Twitter troll pumped full of Newsmax nuttiness. With it, he’s issuing a call to arms as a prominent member of an elite Washington club of 435.

The road to political power for Cawthorn, who has been accused of multiple instances of inappropriate sexual behavior and even lying about the car wreck that left him paralyzed, began not long after the 2010 elections. He has denied those allegations. That year, Republicans spent more than $1m on a dark-money, negative-ad driven effort to win control of North Carolina’s house and senate just in time to dominate redistricting. When they won, a determined Republican party focused on drawing a congressional map that would turn this moderate state inside-out – producing 10 reliable Republican seats and just three Democratic districts.

The key to the entire map? Asheville, the largest city in western North Carolina, an enclave of vegan restaurants and independent bookstores surrounded by conservative mountain towns. With Asheville as its core, the 11th district had long been a swing seat, see-sawing between a Republican from 2000 through 2004 and a Democrat during 2006, 2008 and 2010 as this area, like so many others, rallied behind the Iraq war and then shifted Democratic as the war and economy soured. Republicans needed to win the 11th to assure a 10-3 map. So they drew the district line straight through Asheville, neatly attaching half of the city to a larger number of rural, conservative towns, and diluting the Democratic vote across two districts they could never hope to win.

In a district like this, the Republican primary was now the only race that mattered; the Democratic incumbent saw the writing on the wall and promptly announced his retirement. A small-town businessman who had dabbled in meteorology, a local sandwich shop and real estate read the angry base of this new district perfectly. His name was Mark Meadows, and you can watch on YouTube the moment when he first tasted power. Meadows’s closest Republican competitor dissembled when a Tea Party audience asked about pursuing an investigation into Barack Obama’s citizenship. Meadows pounced with a quick, direct answer: “Yes.” As the crowd roared, Meadows gives a tiny smirk. “You know what?” he added. “We’ll send him back home to Kenya or wherever it is.”

When Meadows led an Obamacare rebellion that forced a government shutdown in October 2013, Karl Rove called the insurgent Republican members his redistricting strategy helped create a “suicide caucus”. The New Yorker took a look at the districts they represented, and discovered a kind of America in reverse – whiter, more rural, more conservative, at a time when demographic trends were headed the other direction. These districts became 2% whiter ahead of 2012. They were 75% white, on average, compared with 63% elsewhere. The Republican party engineered themselves a fantasia: Obama defeated Mitt Romney by four percentage points nationwide. But not in “suicide caucus” nation. There, Obama went down to a stunning 23-point defeat.

That’s what Cawthorn inherited when Meadows left Congress for a seat at Trump’s side as White House chief of staff: a district Republicans cannot lose, where red meat and outrage are all that matters, demographics and representativeness be damned. Cawthorn learned his lessons well. Generate outrage, generate attention, generate big dollars fundraising off the hate.

The census numbers released last month show a nation that continues on its path to diversity. But can a multiracial nation become a multiracial democracy? Not if we continue to redistrict in this toxic fashion. The connection between gerrymandering and polarization is a complicated one; they act as accelerants on each other. Yet there’s no denying this: Cawthorn and his ilk would not be in office without it. There is a huge difference between the kind of candidate who won this very seat a decade ago, and the two extremists who have held it for the last decade. And when we lose swing seats and bridge builders to those who urge Americans to stockpile weapons and ammunition, we have lost an important part of ourselves.

As the 2021 redistricting cycle gets underway, and the maps that will define our politics for the next 10 years are crafted in state capitals nationwide, Cawthorn’s dark vision hangs in the balance. If lawmakers continue to draw tilted maps that maximize the number of seats their party wins, at the cost of representative results in otherwise competitive states, they will continue to produce districts easily captured by ultra-radical zealots like Cawthorn. They will continue to incentivize elected officials to cater only to the militant base that drives party primaries. And we could break, once and for all, under the strain of this existential test.

• David Daley is the author of the national bestseller Ratf**ked: Why Your Vote Doesn’t Count and Unrigged: How Americans Are Battling Back to Save Democracy