E. Monroe Ave. in front of the Eugene Simpson Field, the site where a gunman opened fire Wednesday in Alexandria. (Mark Wilson/Getty Images)

When we talk about politics becoming more like pop culture, we’re generally not being complimentary. We mean that politics has become more entertaining, but less substantive. In one respect, though, our political debates could learn a valuable lesson from our conversations about pop culture. As we argue about the impact of violent political rhetoric and cultural depictions of violence, we could avoid some obvious pitfalls if we could just remember past conversations about the impact of pop culture on mass killers.

The rush to make tenuous connections between political speech or pop culture and specific acts of violence is almost always misguided. But just because we can’t break a killer’s motivations down to a line in a speech or a scene in a movie doesn’t mean we should stop exploring them. Instead, we should treat ugly political rhetoric or the popularity of disturbing culture like a valuable barometer for what’s happening in our environment.

I understand the impulse to assign a share of responsibility for heinous attacks to the cultural, political and media influences on the people who carry them out. When a mass shooting or a political assassination takes place, we are desperate to understand why someone would shoot up a baseball game, a movie theater, or a university. And often, we hope that there is something we can do, other than change our intractable gun laws, to prevent such tragedies from happening again.

It’s true that both pop culture and political rhetoric play an important role in shaping the public’s sense of what is normal and what is acceptable. But there is an important distinction between contributing to a warped and dangerous atmosphere and actually waking someone up in the morning, sending them out into the world with a knife or a gun, and supporting their hand as they raise it to strike a blow or fire a shot. And even if all popular entertainment suddenly became PG, or President Trump stopped tweeting, angry, isolated people would still vent their rage on the world around them.

Seung Hui Cho didn’t murder 32 people at Virginia Tech because Park Chan Wook or John Woo made movies. Cho just found visual language in their movies that he tried to emulate after he had already made the decision to carry out his massacre. Jeremy Joseph Christian, who is accused of stabbing three men who tried to stop his anti-Muslim and racist harassment of two teenage girls, didn’t take orders from Trump. He just acted in an environment where ideas that have long lingered under rocks have emerged and taken their unreconstructed place in the mainstream of American politics.

But it also shouldn’t take the attempted murder of members of Congress or a mass shooting to recognize when political rhetoric has crossed the line, or for a cultural image to alert us to a dark impulse.

To take one contentious example, you don’t have to go so far as to blame Sarah Palin for the shooting of former Arizona congresswoman Gabby Giffords to say that it was unattractive for Palin’s political action committee to use gun sights to mark the districts of Democrats it intended to target in the 2010 midterms. Treating the peaceful, democratic political process as if it’s a blood sport is degrading to the norms that govern our elections. The stakes in our politics are real and substantial. We can acknowledge that and fight fiercely for the outcomes we prefer without using design that suggests that our opponents need not just to be defeated, but eliminated.

Even if Jared Lee Loughner had never picked up a gun and headed to the constituent meeting where he shot Giffords in 2011, that map would have had no place in reasonable American political discourse. No one needs to assert a totally unproven connection between a Facebook image and an assassination attempt to make that clear.

In a similar way, the reason I’ve spent so much time parsing images that depict or refer to Trump’s assassination is not because I’m tracking them because I think they can predict crime. Instead, it’s because the impulse to make those images, and the strength of the response to them, tells us something about the mood in the country as a whole.

That artists such as Snoop Dogg and Kathy Griffin thought images of a presidential assassination might prove popular suggests they sense a deep current of animus towards the president. And that the Public Theater decided to stage a production of “Julius Caesar,” a play that argues that political violence leads to ruin, depicting a Trump-like figure’s assassination implies that director Oskar Eustis saw that animus heading to a dangerous place.

If we do see further political violence after the attack on a congressional baseball practice, neither Snoop Dogg, nor Griffin, nor Eustis will be responsible for that person’s actions. Even if such a dreadful thing never comes to pass, as I fervently pray they won’t, their work will have provided an important barometric reading of the national weather. Either way, we should heed the readings.

If we can’t see that something is ugly and corrosive without it being underlined and punctuated in blood, we are truly in trouble.