This situation is far from a surprise. Most recent polls had shown Macron in front, with Le Pen not far behind, and French presidential elections have gone to a second round every year since 1965, when the current electoral system was implemented. Make no mistake, however: This is already an election for the history books.
And if you look at the chart above, you will see why.
Since the Fifth Republic moved to a direct popular vote method in 1965, the French presidency has been won by a candidate representing either the major center-right political parties (now represented by the Republicans) or the major center-left parties (now the Socialists). Yet this year, neither of those major political groupings will be seen in the second round.
Instead, we are likely to see the independent Macron and his En Marche! (Forward!) movement face off against Le Pen, the leader of a once-fringe right-wing movement founded by her father in 1972. This year's election will be the first in which no representative of the Republican-aligned or Socialist-aligned parties makes it through to the second round.
It is also only the third time that a party representing something other than these two major wings of French politics has entered the second round. The most recent example of a “third party” entering the final round occurred in 2002, when Le Pen's father, Jean-Marie, led the National Front to an unexpectedly good result in initial voting but suffered a landslide defeat in the runoff.
The French political world isn't quite the two-party system we see in the United States. Both the Republican-aligned parties and the Socialist-aligned parties have a complicated organizational history. The Republican party was formed after the 2015 renaming of the Union for a Popular Movement (UMP), which was itself formed by the merging of parties that could trace their ideology to conservative supporters of Charles de Gaulle, founder of the Fifth Republic.
The Socialist wing of France had its own evolution over the years, with the Convention of Republican Institutions (CIR) led by François Mitterrand in 1965 merging with other like-minded parties in 1968 to form the Parti Socialiste, or the Socialist Party. Third parties like Le Pen's National Front had long been able to influence politics to a considerable extent, too, in part because of the runoff system used both in presidential and parliamentary elections.
However, not so long ago, many experts had argued that this quasi-two-party system was strengthening rather than weakening. What happened this time around?
In the Republicans' case, the issue may have been the candidate. François Fillon had run on a platform of traditional Catholic conservative values in a changing France, but his promises of fiscal responsibility and stability took a major hit after allegations that he paid his wife and children 900,000 euros (about $948,000) of government money for work they never did.
Meanwhile, Benoît Hamon of the Socialist Party seemed to struggle because of his association with incumbent François Hollande, a Socialist, who had seen record-low approval ratings as the economy remained sluggish and the country was hit by terrorist attacks. Hamon had also tried to court the far-left vote but struggled against a more charismatic leftist, Jean-Luc Mélenchon.
However, the collapse of the mainstream French parties this year also seems to fit into a broader trend of the fragmentation of European political parties, most recently seen in the scattered results of the Dutch parliamentary election in March.
Either way, the situation lends an air of unpredictability to not only the presidential race, but also the coming parliamentary elections in France. Traditionally, the party that takes the presidency has aimed to take Parliament, too — the periods in which they cannot are known as “cohabitation” in France and tend to feature political deadlock. Without the backing of a major party's political apparatus, a President Macron or President Le Pen might struggle with an uncooperative legislature, though as a centrist and former Socialist, Macron is likely to find more willing allies than his far-right rival would.
And it begs the question: Is this a blip, or the new normal?