A terrorist attack in Paris yesterday - the sixth in the last 3 years - may have an impact on the first round of voting for president on Sunday, analysts say. Political campaigning was suspended following news of the attack.

A policeman was shot in the head and killed by a Muslim attacker who was known to authorities as an Islamic radical. Two other cops were wounded, as was a tourist. The attack took place along the historic Champs-Elysees. An attack last January occurred near the Louvre.

It was the sixth terror attack in Paris in the last 3 years.

ISIS claimed responsibility for the attack, but at this point, it is unclear if the attacker, 39-year-old Frenchman Karim Cheurfi, acted alone or not.

It so happened that the major candidates for the presidency were engaged in a TV debate at the time of the attack, giving the French voter the unique opportunity to weigh the immediate responses to the attack by the candidates.

Fox News:

Thursday’s attack unfolded as the candidates appeared on a television news program. Although campaigning was stopped due to the incident, their appearance offered a unique opportunity for voters to see their immediate reactions.

Le Pen repeated calls for a crackdown on radical Islam, which Macron pronounced “nonsense.” Fillon called for greater cooperation with Russia and Iran and Melenchon warned that France must not give in to violence.

Although the attack left only one police officer and the killer dead, terror has been on the minds of the French for years. A January 2015 attack on the offices of Charlie Hebdo, the satirical magazine targeted after mocking Islam, left a dozen dead. That was followed later in the year by coordinated attacks that killed 130 in Paris. Several other attacks have unfolded in France since then, including the shocking murder of a priest in his church in Normandy and a truck attack in Nice that killed 84.

Fillon’s position is closest to Le Pen’s, offering voters the possibility of a tough-on-terror choice without the far-right association Le Pen carries, in part due to the fact her extremist father founded the party.

“We are in a war that will last: The enemy is powerful, its networks are deep, its accomplices live among us,” Fillon said. “Some don’t seem to have understood the depth of the evil that’s attacking us and that I intend to combat with an iron fist.”

Logic and conventional wisdom say that the most fervent anti-terrorism candidate, Marine Le Pen, should benefit from the attack. Indeed, the latest polls show Le Pen and centrist Emmanuel Macron in a virtual tie for the top position at 24% and 23% respectively. Both candidates have put a little distance between themselves and the other two major players, conservative Francois Fillon and Communist Jean-Luc Mélenchon, both of whom stand at 19%.

Since no candidate is expected to get 50% of the vote, the top two finishers will square off on May 7. Polls also show Macron winning easily in a match up with Le Pen.

But Macron doesn't have anything in the bag yet. First, nearly 1/3 of the French electorate is undecided - even just days before the election. That's an historic number and shows just how volatile the electorate is.

Secondly, while Le Pen's support is solid among her base, Macron seems to be getting a lot of votes from the "anyone but Le Pen" faction of the electorate. His base of support is wobbly and in a second round of voting, anything could happen.

That's where the terrorist attack yesterday might play a role in the election. French security is on high alert, expecting something to happen during the vote on Sunday. They have already uncovered at least one plot to disrupt the vote, and there are likely more. An attack on the heels of the murder of a policeman by an Islamic radical would make Le Pen's anti-terrorist rhetoric resonate a lot more. It might even convince enough voters to look beyond the anti-Semitic history of the National Front and Le Pen's father to embrace the daughter.