Charlie Kirk, one of America’s leading conservative activists and a close friend of President Donald Trump’s son Don Jr., has been murdered. We do not yet know who did it, or why. We do not know how the Trump administration will respond.

What we do know, however, is that there are good reasons to be afraid.

When a prominent political figure is assassinated, the very foundations of democracy come under attack. Democratic politics is, at its heart, a system for containing political violence: a system for resolving the inevitable deep disagreements between citizens without anyone resorting to bloodshed. It works when all major factions believe that the others are committed to following the rules of the peaceful political game; when that belief erodes, it breaks down.

In the past, the American democratic consensus has been strong enough to survive assassination attempts. Some, like the murder of Martin Luther King Jr., tested its bonds but didn’t break them. Others, like the assassination of John F. Kennedy Jr., may actually have strengthened them by creating a sense of shared grief and solidarity.

But now the American political system is crumbling, and many of its tools for containing political violence lie shattered. This probably will not be the event to break America, but we have to consider the possibility that it may be.

The democratic compact today is undeniably weak. The two major parties and their supporters increasingly see each other not as partners, but existential threats to one another’s way of life. Political scientists Lilliana Mason and Nathan Kalmoe have shown that, while few Americans outright support political murder, a growing fringe in both parties have become open to using violence against their partisan enemies.

Under conditions of extreme polarization, when the guardrails of mutual democratic toleration are blown to bits, it is all too easy to see how things could spiral out of control. Leading right-wing figures are not only already prematurely blaming the attack on “the Democrat party,” but also calling for law enforcement crackdowns on liberals and leftists as a group. If Trump acts on these calls, it would further damage the democratic respect that stands between us and the abyss. Future rounds of political violence would become increasingly more likely. Violent breakdown of the democratic order would loom.

How likely is any of that? I’m not sure.

Think back to when Trump was shot on the campaign trail last summer. Nearly everything that I’ve just said about the fraying of the democratic order was true then, right down to top Trump allies immediately, and without evidence, blaming the left. Yet the assassination attempt did not inspire a wave of attacks, nor did it imperil the democratic process.

Something similar could happen this time around too. There may be neither copycat nor retaliatory attacks, and the Trump administration may not ultimately use this as a justification to crack down on its political enemies. This would fit a historical pattern: As the political scientist Dan Trombly points out, America has long had much lower levels of political violence than you’d expect given the prevalence of guns and deep partisan animosities.

But I also think it’s undeniable that our odds of something going wrong are worse now than they were last year.

This is partly because we’re dealing with an assassination — a horrific murder — rather than a near miss. It’s partly because we do not yet know the shooter’s identity: Had the Trump shooter been clearly politically motivated, 2024 could have gone much worse than it did.

But it’s also because our democratic decline has progressed considerably in the past year.

It is undeniably true that Trump has undermined the nonpartisan structure of the American state, concentrating power in his own hands — including over law enforcement and the military. Democrats have, as result, become increasingly less confident that the democracy will survive his presidency — that they can trust Republicans to abide by the rules of the game. There has never, January 6 included, been a more dire moment for the modern American republic than the second Trump administration.

So I cannot be confident that things will turn out the way they did last summer. It is possible that they do. Under normal circumstances, I would be confident that they will.

But I cannot be. Our system is too decayed, too shot through with mutual distrust, to count on democratic faith to get us out of this one.