Donald Trump’s claim that the upcoming election is rigged against him is without precedent in modern US history. The potential consequences are bigger than you think.

The GOP candidate’s talk of “millions” of fraudulent votes and his commitment to only accept the election results “if I win” don’t sound like the words of a typical American politician, and for good reason: The typical American politician has faith in the system, accepts the results of an election, and moves on.

Trump is doing something very different, pairing rhetoric about a rigged election with a message that basically says it’s him or the apocalypse. He has repeatedly warned his fans that if he loses, the America they know will be irreparably damaged.

Those kinds of words can have serious real-world impact. A range of scholars who study everything from civil wars to the history of the Ku Klux Klan each expressed deep concern about potential consequences ranging from murders at polling booths to the rise of a new racist terrorist movement to the weakening of the long-term stability of the American political system.

It’s important to emphasize that none of these outcomes is especially likely. If Trump loses, as now seems quite likely, things will probably be fine: Mass violence can only erupt under a specific set of circumstances, and American democracy has withstood an actual civil war, not to mentions decades of racially motivated unrest. Many right-wingers are also known for talking a big game but then ultimately backing down without a fight.

But it’s the “probably” that keeps me up at night. Trump is making some pretty catastrophic events more likely than they should be. And that should really scare us.

“It really is hard to think of democratic politicians who’ve done this — anywhere,” says Shaun Bowler, a professor of political science at the University of California Riverside who studies the behavior of parties that lose at the ballot box. “He’s done quite a bit of damage already.”

It's not just a campaign about who will be the president anymore. It's a campaign about what kind of country America will be after the votes are cast.

There is a serious risk of violence on Election Day, and it is Trump’s fault

The first major test of Trump’s inflammatory language about a stolen election will come on Election Day itself. Trump has been encouraging his supporters, who are heavily white and non-urban, to “go around and watch other polling places.” He has specifically told his supporters to watch polling places in urban areas; the racial subtext isn’t exactly subtle.

“I hear these horror shows, and we have to make sure that this election is not stolen from us and is not taken away from us,” he said at one rally in Pennsylvania. “And everybody knows what I’m talking about.”

Basically, Trump is encouraging his voters, already anxious about a possibly “rigged” election, to go out to polling places full of non-Trump voters and serve as amateur election police. These people can’t go into polling places, legally speaking. But they can congregate around polling places, showing up and harassing voters waiting in line.

It’s a situation you can easily imagine escalating out of control.

A fight breaks out between a Trump supporter and, say, a Black Lives Matter advocate — and one of them is armed. A radical Trump supporter, perhaps a member of a far-right militia or neo-Nazi movement, shows up at a polling station with the intent of using force to stop minorities from “rigging” the vote. It could also go the other way: A Hispanic American or African American tired of being demonized by Trump could see one of his supporters and go looking for a fight.

Trump “claims that the stakes are so high, the situation is so extraordinary, that some form of intimidation, presence, provocative behavior is necessary to preserve the republic, preserve civilization,” says Paul Staniland, a University of Chicago professor who studies violence and civil conflict. “This kind of rhetoric raises the probability [of electoral violence]. I’m comfortable drawing a straight line.”

Indeed, some of Trump’s supporters — especially from the loose-knit network of far-right political groups and militias -- are now openly talking about post-election bloodshed. According to a January count by the Southern Poverty Law Center, there are 276 such militias operating in the United States. A review of 240 militia group Facebook pages by researcher Jonathon Morgan found a spike in their online activity in recent months — with some members openly warning of the need for violence if Clinton wins.

“If she wins ... it’s over, time for a revolution,” one militia member writes, according to Morgan. “Enough of being tough on the blogs, be tough in real life.”

Trump and his aides consistently and angrily deny using irresponsible language that raises the risk of civil unrest. The problem is that violence could erupt all the same because of the atmosphere of paranoia that Trump has helped create.

Trump’s rhetoric surround his plan to ban Muslim immigration, which often implies all Muslims are potential terrorists, is a case in point. A new report from the Center for the Study of Hate and Extremism at California State University San Bernardino found that 2015 saw the highest rate of anti-Muslim hate crimes since the period directly after 9/11.

Some of that is doubtless due to the hundreds killed by ISIS terrorists around the globe, including the 49 people massacred at a gay nightclub in Orlando in the worst terror attack in the US in more than 15 years. But experts say Trump is leading many of his supporters to use those attacks to conflate ISIS with Islam and treat ordinary Muslim Americans as potential threats.

“This could escalate very quickly”

“You have politicians talking about deporting Muslims and saying that the vetting process isn’t good enough,” Daryl Johnson, a former Department of Homeland Security analyst and expert on right-wing violence, told the Kansas City Star. “So people start thinking that ISIS is around every corner.”

There’s an X factor in the United States that makes the situation particularly scary: guns.

The United States has the highest rate of gun ownership in the world, by far. I don’t mean in the developed world: The country with the next closest level of gun ownership is Yemen, which has a little over half as many guns per person as the United States.

Laws in many states allow people to carry their guns with them, either concealed or openly, even during political demonstrations. Many gun owners explicitly see their firearms as checks on potential government tyranny.

There’s just no analogous situation to this, especially where a leading politician is explicitly encouraging his followers to see the electoral system as corrupt and broken.

“You have preexisting, organized, armed militias who have said that they might see it as their duty ... to attempt violently to topple the government or kill the president,” Jay Ulfelder, a political scientist who studies democracy and violence, says. “I can’t think of any other case where there’s been something like that, either in a developed democracy or less [developed one].”

The prevalence of gun ownership makes Trump’s rhetoric far riskier. In one scenario, as Ulfelder suggests, you have right-wing radicals actively believing that Trump is encouraging them to take up arms against their own government. In another, the presence of guns could cause a fight between two citizens to turn from punches to bullets.

In the truly scary scenario, one or several such incidents get amplified, inspiring other acts of violence either on Election Day or directly afterward. Then you get a wave of violence around the country.

“This is what I worry about with social media and the media in general,” Staniland frets. “This could escalate very quickly across a wide variety of localized areas. I think that’s the big danger about short-term violence linked to this campaign.”

The US is no stranger to political violence

If bloodshed erupts on Election Day, it will be a dark echo of an earlier and much more tumultuous period of American history.

Most Americans have forgotten how rough our elections used to be. But early in the republic, political violence was the norm, not the exception. “Until 1896, not a single Election Day passed in the United States without someone getting killed at the polls,” historian Jill Lepore writes in the New Yorker.

The most notable period of election-related violence came during Reconstruction, the Northern effort to rebuild the South after the Civil War and empower black citizens. The postwar attempt by black leaders to organize for elections and political participation directly led to the rise of groups like the Ku Klux Klan.

The Klan itself was founded in Pulaski, Tennessee — a town that was, at the time, notable for having a relatively wealthy and politically connected black population. Initially, the Klan wasn’t especially violent, serving as more of a social club for former Confederate soldiers. But as time went on and the white population grew more concerned about black social power, the Klan took matters into its own hands.

By the 1868 presidential election, the Klan was regularly intimidating Pulaski’s prominent black residents, showing up at their homes and threatening them with harm if they asserted themselves politically. The goal of this violent turn was to destroy Pulaski’s black civil society, to make sure that black people wouldn’t be able to get to the polls in great numbers or hold political office.

“It becomes clear to [whites] that they’re not going to be allowed to rebuild their own power structure,” says Elaine Parsons, a historian at Duquesne University and the author of Ku-Klux: The Birth of the Klan during Reconstruction. “They can see black groups mobilizing, and so they’re concerned that they’re building up a civic infrastructure.”

This intimidation wave evolved into the South-wide campaign of terrorist violence and murder, most notably lynchings, the group is remembered for.

According to Parsons, the spread of the Klan wasn’t centrally organized by some headquarters in Pulaski. Instead, its branches across the nation were mostly independent, starting up in their town or region basically without direction.

The key factor in its spread? Outsize media coverage of Klan violence, which inspired like-minded whites around the country to take up arms under the Klan banner. Media coverage of one violent attack on black political organizing generated more such attacks.

“Disparate groups organized themselves in response to learning about the Klan in the media,” Parsons says. “It was a pretty organic expression of white fear about black power.”

Trump isn’t just stoking electoral violence — he’s undermining confidence in elections themselves

Those are precisely the types of fears that Trump is trying to capitalize on today, pairing “rigged election” rhetoric with terrifying warnings about the end of America. He has repeatedly told his fans that if he loses, they might not get another chance at a fair election.

"I think this will be the last election if I don't win,” Trump said in a September appearance on the Christian Broadcasting Network. “You're going to have illegal immigrants coming in and they're going to be legalized and they're going to be able to vote, and once that all happens, you can forget it.”

Trump is arguing that his defeat would be proof that the system is rigged against him and its outcome fraudulent and illegitimate. That, the University of Chicago’s Staniland says, “undermines faith in the democratic system, that the votes will be counted in a free and fair way.”

You can already see the impact of Trump’s incessant fearmongering. A September Gallup poll found that only half of Republicans were confident that their votes would be counted accurately, the lowest number ever in a Gallup poll on this issue. A late October poll, from Reuters, found that 70 percent of Trump supporters believe a Clinton victory would be a result of “illegal voting or vote rigging.” Only 50 percent of Trump backers, in this poll, say they’d accept Clinton as their president.

There’s every reason to expect this to get worse in the next two weeks — and even after the election.

Prior to Barack Obama’s election, data showed Republicans having slightly more confidence in the fairness of US election than Democrats. But in surveys conducted during and after the 2008 and 2012 elections, this flipped. Republicans started to believe in widespread voter fraud, like people pretending to be someone else at the ballot box, at higher rates than Democrats.

Faith in the legitimacy of the electoral system is more fragile than Americans generally believe

This can partly be attributed to the elections’ results. A significant number of studies, both in the United States and internationally, show that people’s confidence in the electoral system is determined by whether their candidate has won. So when George W. Bush was elected president, Republicans had more faith in the system; once Obama won, Democrats did.

Republicans have also spent much of the past decade pushing laws requiring voters to show IDs before they can vote, arguing that the US voting system is racked with fraud and requires a legislative change to fix it. Democrats, by contrast, have argued that such changes actually undermine electoral fairness by disenfranchising a lot of poor and minority voters, who tend to have fewer government-issued IDs and a harder time obtaining them.

The result is that the issues of voter fraud and election legitimacy have become highly politicized, with many Republican voters believing that voting fraud is widespread.

These two trends, taken together, are very worrying for this election. First, they tell us that losing undermines voters’ faith in the system. Second, they tell us that many Republican are already predisposed to believe the electoral system is rigged.

Trump is losing — and he’s saying it’s because the system is rigged. His hardcore supporters, who see the electoral system through the lens of how Trump does and what Trump he them about that result, will almost certainly take his rhetoric seriously.

This is why experts on fairness in elections, like Harvard political scientist Pippa Norris and UC Riverside’s Bowler, are so worried about Trump’s rhetoric. They understand that faith in the legitimacy of the electoral system is more fragile than Americans generally believe — so when a major party nominee takes a hammer to it, the candidate can undermine the system far more than you might otherwise think.

Election Day could be bad. What comes next could be worse.

No matter how heated the rhetoric, both sides have historically accepted the outcomes of US elections even when they had reason to question their legitimacy. Consider the 2000 presidential election: Democrats had a lot of good reasons to think the White House was, in a way, stolen from Al Gore. Yet Gore conceded after the Supreme Court ruled in Bush’s favor, and Democrats mostly reconciled themselves to a Bush administration.

What Trump has done is radically different, and the impact of his rhetoric will live on long after November 8, even if that’s all it ends up being in the end — rhetoric.

“There will be a proportion of the American public that views this election as fundamentally illegitimate, even if Trump concedes,” Staniland says. “He’s sowed the seeds of radical doubt, in ways that will be difficult to reel back in even if he wanted to — and I don’t think he particularly wants to.”

Indeed, there’s good evidence that Trump will just keep on Trumping after his likely defeat. His campaign has begun airing a nightly news show on its Facebook page, which is widely understood to be a test run for launching an entire Trump TV station or a digital-only, subscription-based media operation modeled on Glenn Beck’s troubled site The Blaze. Trump’s son-in-law Jared Kushner has already reached out to an influential TV investor; his campaign CEO, Steve Bannon, has played coy when asked about a potential venture, telling reporters that “Trump is an entrepreneur.”

Trump TV would likely continue and amplify the kind of racialized, conspiratorial rhetoric you’ve seen from his campaign — clearly, it’s been a key part of his brand. He would provide a much bigger platform for the fringe right, figures like the conspiracy theorist Alex Jones, than it had before. The network would hammer home the message that the system itself is illegitimate and American democracy is being stolen, beaming it to every hardcore Trump fan with an internet connection.

The potential for long-term damage, from both Trump’s campaign rhetoric and a Trump TV network, are severe. And that’s because they intersect terribly with America’s most fundamental political divide: race.

Trump’s base, according to the best political science evidence we have, is overwhelmingly driven by racial resentment. As the United States has become more ethnically diverse, a portion of white Americans have become increasingly anxious about the future of their country. They feel a sense of loss, of alienation from a society that doesn’t look like the one they grew up in. The result is their support for the most nakedly racist demagogue since George Wallace.

In developing countries, this kind of ethnic power transfer is the exact situation where widespread ethnic conflict breaks out.

A 2010 paper published in the journal World Politics looked at 157 cases of ethnic violence in nations ranging from Chad to Lebanon. It found strong statistical correlations between one group’s decline in status and the likelihood that the group turns to violence against another group. This suggests that eight years of governance by a black president would inflame white racial panic, a sentiment borne out by the data on white attitudes during the Obama years.

According to Erica Chenoweth, a political scientist at the University of Denver, this violence becomes particularly likely when members of the former majority no longer trust political institutions to function fairly. Institutions like, say, elections.

The scenario that kept coming up in my interviews is a resurgence of anti-government, racially motivated terrorism.

In this case, whites inspired by Trump’s rigged election rhetoric form militant groups, or join existing militias, as a way of retaking their country from Clinton’s heavily minority coalition. If they believe the system no longer treats them fairly, they might decide to attack it.

“If Hillary wins, I think you will see civil violence [targeting] the government,” Chenoweth says. “That’s my political science prediction.”

Parsons, for her part, sees a lot of similarities between what’s happening right now and the sort of backlash that fueled the KKK’s popularity during Reconstruction.

“It’s very scary; I find this very familiar,” she says. “My suspicion is that the Klan, and Klan groups, will in fact be coming back in a fairly substantial way. ... The Klan is the tip of the iceberg of an anti-black anxiety that Trump is fueling.”

It’s import to recognize that the vast, vast majority of Trump supporters — even those with racist or anti-immigrant views — are unlikely to turn to violence in any form. But it doesn’t take many people to mount a sustained campaign of anti-government or anti-minority violence. It just takes a few determined people, and communities that are alienated enough from the system to shelter them. Think of the Oklahoma City bombing, for example.

“You don’t need that many people to basically start a major national crisis,” as Chenoweth puts it.

Of course, this is just one possible outcome. Predicting the long-term effects of something like Trump’s rhetoric is extremely difficult. Statistics aren’t wizardry, and political scientists don’t have crystal balls.

The point, more fundamentally, is that mucking with the democratic system itself is extremely dangerous. Democracies are not invulnerable, especially ones that have been riven by ethnic divides for literally their entire existence. The effects of undermining faith in the system, the thing most responsible for keeping the peace, are in many ways totally unpredictable.

“There’s potential, between a variety of social movements and a lot of armed citizens, for really some pretty surprisingly unstable dynamics to emerge,” Staniland says. “It’s not that far in the history books.”

Will this lead to some kind of major crisis, created by right-wing terrorism or some other social unrest, that threatens to sunder American democracy? Like any long-term prediction, it’s difficult to say with confidence — and I don’t want to be alarmist, issuing Cassandra-like warnings of a crisis that’s fairly unlikely to happen.

But the fact that we’re even talking about this, and political scientists and historians are taking it seriously rather than laughing it off, is quite telling.

“After the wave of democratization 20 years ago, what you got was all kinds of people from Ukraine, Argentina, Mexico — all of those places that didn’t have strong institutions — looking to the US for examples,” says Bowler. “We’re talking to people now who are experts on Ukraine, or Mexico, for lessons about what’s going to happen in the US. That, in itself, is a very worrisome fact.”

Trump is attacking the core democratic institutions that it has taken Americans years to build up, raising issues about electoral legitimacy and trust in the system that are basically unheard of in longstanding, wealthy democracies. Clinton is likely to win the election. But American democracy might end up losing all the same.