On Tuesday morning, explosions at the Zaventem airport and the Maelbeek metro station in Brussels, Belgium, killed more than 30 people and wounded more than 200 more. Hours later, the Islamic State claimed responsibility for the attacks, which marked the group’s second massive-scale terrorist offensive since last November’s attacks in Paris, France.
What impact can we expect the Brussels attacks to have on our presidential primaries? To investigate, let’s first consider how similar attacks in Paris affected the race late last year.
This first chart compares polling done prior to Paris with polling done after Paris. Specifically, it looks at pollsters who conducted polls both before and after, but only within a 30-day period in either direction.
Every single comparison showed at least a five-point bump for Donald Trump, with four of the six pollsters profiled registering a bump in double-digit territory. That’s a remarkable turnaround. But within a 30-day period there were more than just six polls conducted. The above chart looks at six in order to give a sampling. Let’s look at them all.
The Paris attacks, which took place on November 13, represented a pivotal event for Trump, enabling him to reclaim the polling lead he enjoyed prior to Ben Carson’s surge in mid-to-late October. We see a clear upswing for Trump post-Paris. In the above chart, you can hover over each data point to see Trump’s lead (or deficit) in each individual poll, the whole series of which are arranged chronologically. I look at 11 polls done in the 30 days prior to Paris, and 11 polls done in the 30 days after. The results show that Paris correlated with a significant positive effect for Trump’s candidacy.
The Attacks Also Shifted the Debates
In addition to polling, we can take a look at what preoccupied the Republican Party before and after Paris by tallying up the amount of times “ISIS,” “Islam” (and its cognates), and “terror” (and its cognates) were uttered in the Republican debates. What do we find?
In the October and November debates, which took place prior to Paris, these issues were not front and center; in the December debate, they most certainly were. In the above graph, you can click on each term to see how many times it was uttered in each of the three debates (the October debate had zero mentions of the latter two terms).
The October 28 debate was the infamous CNBC debacle, and the three terms received three measly mentions, combined. The November debate, which took place just three days before the Paris attacks, contained 20 total mentions. Admittedly, the November debate was focused on economic questions; after all, it was hosted by Fox Business News in combination with The Wall Street Journal.
Yet both of these outlets regularly provide commentary on foreign policy, so it’s not as if the low mentions can be entirely explained by considering the night’s overriding focus. The December debate, which took place a month after Paris and focused on foreign policy, produced 232 mentions of these terms. It’s clear that Paris intensified interest in discussing Islamic terrorism, at least on the Republican side.
We can also see that the Google search interest for these terms was greatest around the middle of November, in the immediate aftermath of the Paris attacks. The following graph filters out any searches not done on American soil.
Effects on Trump Versus Carson and Cruz
Although this is hardly surprising, I include it in order to investigate what about Trump caused his numbers to go up in response to Paris. Perhaps Trump’s rise had less to do with Trump and more to do with who his chief opponent was at the time: Carson. Indeed, around that time reports had surfaced about Carson’s ongoing struggles with grasping the intricacies of American foreign policy concerns. His own foreign policy advisors were publicly announcing Carson’s deficiencies in this area.
There’s no evidence that in the aftermath of the Brussels attacks, Ted Cruz, who is currently Trump’s biggest rival, will see his numbers go down the way Carson’s did back in November. When we look at exit polling data from CNN, it shows voters who prioritize “terrorism” as the most important issue in this election rate Cruz very highly.
In my five-state sample, I make sure to include the first three contests in order to not skew the results against Carson, who after February was even less competitive than he was initially. Cruz does better than Trump in Iowa, gets blown out in New Hampshire, stays competitive in South Carolina, matches Trump in Oklahoma, and stays right on his trail in Illinois. The point isn’t necessarily to show how Carson’s numbers are low in comparison to Cruz’s, but to show how Cruz is very competitive with Trump on the issue of being tough on terrorism, according to the voters.
Extreme Responses to Extreme Actions Seem to Work
But let’s assume that Trump’s November rise wasn’t just due to an underwhelming rival in Carson but also due to Trump’s own abilities to generate support as a strong leader. Yet it’s not clear that the Paris event itself, as opposed to related but separate concerns that emerged out of it, was responsible for Trump’s reemergence as the clear leader in the national polls.
Consider that Trump used the Paris attacks to introduce a series of escalating anti-immigration ideas, beginning with a call to ban Syrian refugees from entering the country (November 17), a promise to monitor mosques using law enforcement surveillance and to re-implement waterboarding as an interrogation tactic (November 22), and finally to ban all Muslims from entering the country (December 8). It’s likely that these positions played a major role in Trump solidifying his status as GOP front-runner.
The Paris attacks gave him the opportunity to apply his anti-immigrant platform, and he did, which means the attacks themselves weren’t responsible for his rise, strictly speaking. This is a subtle but important consideration, since it suggests he may not see a bump in response to the Brussels attacks unless he finds a way to harness them into an inspiring (well, inspiring to fearful voters) anti-immigrant message.
The problem is that while in November the Syrian refugee crisis was a prominent news item, there is nothing of comparative newsworthiness going on today in that same category. The question of whether to embrace Syrian refugees has largely receded from the current news cycle. This means whatever Trump says in response to Brussels might come across as contrived, or at any rate less inspirational to some Republican voters, than what he said late last year proved to be.
In Destabilizing Times, People Seek Leaders
Of course, it’s hard to use the data we have to confidently predict what will occur going forward. This is not due to a deficiency in the data, but rather due to the nature of the 2016 elections. A 2001-2004 study by the sociologist Robb Willer found that government-issued terror warnings generated a bump in support for the president. Willer’s conclusion is that “fear of external attacks leads to increased support for standing leaders.” Yet the 2016 race doesn’t have an incumbent running.
In a 2009 study, political scientists Jennifer L. Merolla and Elizabeth J. Zechmeister found that terror threats cause voters to weight leadership into their decision more heavily than they would during “good times,” defined as a period characterizable by “positive indicators about the economy, health, and the environment.” Terror can even destabilize, the same researchers find in a later study, the stability of democracy within a regime and can erode confidence in democratic norms among a citizenry.
But what makes all of this hard to apply to this year’s race is that it’s unclear what sort of leadership voters will prefer: Trump’s corporate leadership combined with a rhetorical strategy that eschews political correctness and evokes nationalistic fervor? Or Hillary Clinton’s executive leadership combined with a rhetorical strategy aimed at avoiding inflaming hostilities between us and the broader Muslim world? Or can Cruz, whose numbers on terrorism are solid, emerge to rally the “strong leadership” vote then bury Clinton with her record of foreign policy missteps?
We will have to wait to find out.