The attack Thursday on the Champs Elysées in Paris, three days before Sunday’s presidential election, resulted in headlines about the impact it would have on the vote—“How Paris police shooting could shape French election,” “Will the Paris Attack Help Le Pen Win the French Presidency?” “The French terror attack could benefit Marine Le Pen”—as well as this prognostication from President Trump, who told The Associated Press he believed the attack will “probably help” Marine Le Pen, the leader of the far-right National Front (FN), because she is “strongest on borders, and she’s the strongest on what’s been going on in France.”

The FN, a longtime fringe presence in French politics, has tried to shed its reputation as an anti-Semitic party. Le Pen has criticized many of the same developments that Trump denounced during his campaign: globalization, open borders, immigration, and free trade. Those positions have propelled her to near the top of opinion polls. She is predicted to be one of two candidates who will reach the second round of the French election in May. (There are 11 candidates in Sunday’s election and none has enough support to secure the 50 percent needed to avoid a runoff.) So will Friday’s attack help Le Pen as news  headlines and Trump have suggested?

In general, voters in countries hit by attacks list terrorism as among their top areas of concern. And, political scientists have found, terrorism benefits conservative candidates more than it does liberal ones. Robb Willer, a professor of sociology at Stanford, told Stanford News: “Conservative positions on a variety of issues, including national defense, military funding and immigration, are more popular during periods of heightened terror threat. Further, conservative politicians are more likely to support militant foreign policy positions than liberals, while liberals are more likely to support diplomatic solutions. These policy orientations lead conservatives to gain increased support during times of heightened security concern.” Willer’s remarks were restricted to the U.S., but similar results have been seen in Israel in a study by Claude Berrebi and Esteban Klor, who found the “the relative support for the right-wing party … increase[d] after periods with high levels of terrorism and … decrease[d] after periods of relative calm.”

Such data would suggest that Thursday’s attack would favor Le Pen over her main centrist rival, Emmanuel Macron.

But there is very little data for an election conducted in the immediate aftermath of a terrorist attack. Attacks in France in 2015, a month ahead of regional election, and in 2012, a month before the presidential election, had little impact on the outcome—which in each case reflected what polls predicted prior to the attacks. One other example we have is Spain in 2004. Three days before the country was set to vote in general elections, near-simultaneous attacks on Madrid’s commuter train system killed 192 people and injured more than 2,000—far more than the one person killed and two wounded in Thursday’s Paris attack.

Spanish authorities said al-Qaeda was behind the attack—though no direct link was ever revealed. The ruling center-right Popular Party (PP), which had won the previous election in 2000 with a comfortable majority, lost to the center-left Socialists (PSOE). The results were seen as a stunning upset. Many observers said the terrorist attacks had cost the PP the elections. The reality was more complicated, however: Spain’s involvement in the U.S.-led war in Iraq was extremely unpopular, as was the government’s performance over the past four years. In the run-up to the vote, the PP’s lead in the polls was narrowing; some polls showed it and the PSOE neck-and-neck. Then came the March 11 attacks. Spaniards immediately rallied around the flag. But when the PP government blamed Basque separatists (ETA) for the attacks, the mood turned. The turnout in the elections jumped and PP lost its majority. The PSOE, which saw its vote share increase, formed a coalition government.

As political scientists Ignacio Lago and Jose Ramon Montero wrote in a working paper for the Institute of Political and Social Sciences:

Whatever the case, it must be remembered that if the attacks had not taken place, either the PP or the PSOE could have won the election …

These reactions did not happen in a vacuum. They were conditioned by the also negative evaluations of the incumbent performance over the preceding four years. The results are conclusive. Every policy, barring economic and employment policy, was viewed negatively. This retrospective judgment became a sufficient condition for the PSOE to win former IU and PP votes, for former abstainers to participate, and for young voters to mobilize in the wake of the terrible commotion caused by attacks, and for which government was blamed.

In other words, while the terrorist attacks might have tipped the balance toward the PSOE, there had been several underlying factors leading to the Socialist victory. Many of those same underlying factors are present in France. There’s anger at the ruling Socialists, whose incumbent President Francois Hollande is so unpopular he didn’t run for re-election. The Socialist candidate is among the political also-rans. There’s also anger at the center-right Conservatives, whose candidate Francois Fillon once led in the polls, but now is in third place, felled by a political scandal. There’s anger that France has never quite become the dominant EU country (that honor is Germany’s). There’s anger at immigration and refugees, the state of the economy, unemployment, and the apparent ability of terrorists to strike at will. In short, as Roger Cohen wrote last Sunday in The New York Times: “For some time France has been a country that does not like itself.”

That self-loathing has already had political consequences: It’s all but certain that the next French president will not be from one of the two parties that have dominated politics since the end of World War II. Instead, the two front-runners are Le Pen, who would become France’s first far-right leader since the war, and Macron, a centrist, globalist neophyte, who is marginally ahead in most polls. In other words, a political outsider will be France’s next president.

Le Pen is likely to repeat her father Jean-Marie Le Pen’s stunning performance in 2002, and reach the second round in May. Most polls show her getting trounced—much like her father was by against Jacques Chirac. But with between 27 and 40 percent of voters undecided, disgruntlement with the existing system, combined with the seemingly ever-present threat of terrorism, Le Pen may prove her critics and the polls wrong.

But there’s another possibility to consider: That terrorist attacks become so commonplace that, despite their nature, the public shrugs off the minor ones. We’ve already seen that to some extent in the financial markets, which these days barely register even medium-sized attacks. There have been more than a dozen terrorist attacks in France since 2014, resulting in the deaths of more than 200 people. Thursday’s attack was by no means the most shocking, but could it galvanize voters to choose a candidate whose party they’ve previously rejected as unpalatable? We’ll know next month.