Story highlights France's presidential election is set for a runoff to take place on Sunday, May 6

Incumbent Nicolas Sarkozy finished behind Francois Hollande in the first round

A couple of extreme candidates, one far left and one far right, could still affect the outcome

Unemployment is the biggest issue in the race, but immigration and debt are also talking points

It has been 17 years since France had a president from the left, but that might be about to change.

Francois Hollande, a candidate from the center-left Socialist Party, has significant momentum after edging center-right incumbent Nicolas Sarkozy in the first round of France's presidential election on Sunday. If he wins a May 6 runoff against Sarkozy, Hollande would be the first left-wing president since Francois Mitterrand in 1995.

Sarkozy is seeking his second five-year term , following Jacques Chirac, who served 12 years in office. Sarkozy received 27.2% of the vote in the first round of voting on Sunday, just behind Hollande's 28.6%.

As the French prepare for the runoff, here are a few key points to keep in mind:

1. This is a two-horse race, but other candidates matter.

Ten candidates, spanning the entire political spectrum, took part in the first round of voting. But opinion polls always pointed to a runoff between Sarkozy and Hollande. (In France, a presidential candidate must receive more than 50% of the vote to win office. If no one claims a majority in the first round of voting -- and no one ever has, in the current system -- the top two vote-getters advance to a second round of voting.)

But even with the predictable Sarkozy-Hollande finish, it was still important to see how many votes the other candidates received. That's because those votes are now up for grabs in the runoff.

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"The other candidates have to be given some attention because they exert an influence in the race," said Michael Leruth, who teaches a course about the election at the College of William & Mary in Virginia.

Finishing behind Hollande and Sarkozy were two extreme candidates: Marine Le Pen on the far right and Jean-Luc Melenchon on the far left. Le Pen, daughter of 2002 presidential finalist Jean-Marie Le Pen, finished third with 17.9% of the vote. Melenchon finished fourth with 11.1%.

Their strong showings might cause Hollande to tack more to the left and Sarkozy more to the right before the runoff.

"If you're coming out of the first round with 27%, 28%, you need to make it to 50%. So you have to think of where you are going to make up that difference to prevail in the final round," Leruth said.

A day after the first round, Sarkozy said he has a "duty to listen" to far-right voters after Le Pen's third-place finish.

"We must respect the voters' will," he said.

2. One issue stands out among the rest.

The economy dominates the political agenda in France, much as it does in America.

"Basically for months now, the top issues have been unemployment and purchasing power," said Jim Bittermann, CNN's correspondent in Paris.

Jobs have been difficult to come by, especially for young people, and that is one of the main reasons that Sarkozy is vulnerable.

"Even though some people would give Sarkozy high marks for doing the kinds of things that might have a positive long-term effect on the economy -- like raising the retirement age to put the system on sounder fiscal footing -- he hasn't been successful in bringing jobs back," Leruth said.

Comparing Sarkozy and Hollande on their economic policy is not unlike comparing Republicans and Democrats in the United States.

"Hollande is in favor of more government action to stimulate the economy, stimulate spending ... whereas Sarkozy wants to improve the climate for business by lowering some taxes, by talking about repealing the law establishing the 35-hour work week -- a Socialist measure from the late '90s -- to make it possible to work more," Leruth said. "It's more of a private-sector approach."

3. France and America have more in common than just high unemployment.

Immigration, race and the assimilation of France's large Muslim community have been prominent issues leading up to the election, even before the March shootings by an Islamic extremist in Toulouse and Montauban.

Sarkozy has been tough on immigration. Last year, a law went into effect banning Islamic face coverings in public places, the so-called burqa ban . And in a recent television interview, Sarkozy said France has "too many foreigners" and that the country is not integrating them properly.

Sarkozy won the 2007 election by taking a strong stance on race, according to political analyst Simon Persico from the Center of European Studies. But Le Pen, this year's far-right candidate, said Sarkozy hasn't been strong enough while in office.

"Le Pen is saying the original is better than the copy, and that voters should not believe Sarkozy on race," he told CNN.

4. The election's result could affect the eurozone.

Sarkozy has worked closely with German Chancellor Angela Merkel throughout the European debt crisis, leading the way for strict austerity measures in Greece and other troubled countries. Would Hollande's election encourage a change in strategy?

"There is concern that, within the eurozone, Hollande's election could create greater instability," Leruth said. "He's talked about renegotiating some of the accords that have been reached -- at the instigation of Sarkozy and Merkel -- to ensure greater stability in the eurozone."

The reason is long-term growth.

"I think some of the French like the way (Sarkozy) handled -- with Merkel -- the agreement in December to get more rigor, more austerity into European budgets. But then Hollande and other economists are saying we also need growth, and these plans are going to absolutely stifle growth," said Homer Sutton, a French professor at Davidson College near Charlotte, North Carolina. Like Leruth, he is teaching a course on the election.

France's own debt is also a concern. Like the United States, the country recently had its AAA credit rating downgraded. Hollande has promised to create tens of thousands of public-sector jobs and raise taxes on the rich to pay for them. But some are concerned that might encourage the rich to just leave France.

"There's some feeling that if Hollande is elected, the attack on the French sovereign debt could be quite serious," Sutton said. "And this is what Sarkozy has been saying: 'If you elect Hollande, we're going to be losing more than our AAA. We'll be going down even further.' "

5. Franco-American relations should remain strong.

Hollande has pledged to remove French troops from Afghanistan by the end of this year if he is elected. Whether it's a realistic goal or not, that could create some tension between Paris and Washington.

But Hollande is known for being a no-nonsense pragmatist.

"Hollande knows that he needs the United States and that the United States needs Europe, so I think there would be a great deal of cooperation there," Sutton said.

Sutton recalled Mitterrand's election in 1981 and how there were initial concerns about him.

"Everyone said, 'Oh, he's got four Communists in his government, this is going to be the end of the relationship with the United States.' But it turns out that he was a very strong defender of American missiles in Germany, for example," Sutton said. "Mitterrand's friendship with (Chancellor) Helmut Kohl, it was a strong French-German relationship, and (U.S. President Ronald) Reagan and Mitterrand didn't get along too badly despite their ideological differences."