From the NYT:

In Cold Political Terms, Far Right and French President Both Gain

By STEVEN ERLANGER JAN. 11, 2015

PARIS — … If Mr. Hollande has gotten a small boost from these terrible few days, however, so have Ms. Le Pen and the far-right National Front, which has made the challenge of radical Islam to France the center of their politics. Even before the attacks, her brand of nationalistic French populism had helped make her a credible contender to succeed Mr. Hollande in the 2017 election.

The homegrown terrorism here, with its apparent links to Al Qaeda and the Islamic State, will also be used by other far-right, nationalist and anti-immigration movements in Europe, from the United Kingdom Independence Party to the Sweden Democrats and Germany’s Pegida — Patriotic Europeans Against the Islamization of the West. That is another reason so many European leaders from the mainstream parties of the center right and center left, from Angela Merkel of Germany to David Cameron of Britain and Mariano Rajoy of Spain, came to show their own solidarity with France and Mr. Hollande.

Invitees also included the leaders of all the main French political parties, including former prime ministers and presidents, like Nicolas Sarkozy and his rivals on the center right in the Union for a Popular Movement, Alain Juppé and François Fillon, who themselves are divided but also battling for voters attracted to National Front.

Ms. Le Pen was excluded from the Paris rally, however, in what many consider a political mistake by Mr. Hollande’s Socialist Party, which organized the event.

Ms. Le Pen, whose support in various opinion polls for the 2017 presidential election comes close to 30 percent, loudly cried foul. Her exclusion made a mockery of the concept of national unity, she said, and was itself a violation of “freedom of expression,” which the rally was meant to uphold. She accused the political elite of “astounding cowardice” to isolate “the only political movement that has no responsibility in the current situation, nor do its millions of voters.”

“The masks fall,” she said. “National unity is a pitiful political maneuver.”

She said her supporters would see her exclusion as a “tribute” to their power, saying, “They will have the opportunity if they wish to express their opinion at the ballot box.”

Ms. Le Pen’s embrace of exclusion perfectly fits her politics. Using old tropes of the far right in France, she took pride in avoiding the capital, Paris, which she and her supporters view as the center of political corruption and cynicism, for “la France profonde,” the “real France” of genuine patriots tied to their land and their provinces. So she marched on Sunday instead in southern France, in Beaucaire, where her party won local elections.

“We’ll march there where the spirit of tolerance is the strongest,” she said, “where sectarianism is less violent.”

Alain Barluet, a journalist with the daily Le Figaro, said Mr. Hollande had handled the situation well except for his exclusion of Ms. Le Pen.

“The problem for us now is simple: Will she be the next president?” Mr. Barluet said. “Many people are unhappy with the exclusion of the National Front from the march, since she is always emphasizing this fracture — that she is a victim, that she is the real France.” …

The problem, Mr. Rousselin said, is that “the National Front is the only party that is saying out loud things that many people feel, and the current moment is playing into this discourse.” He added, “If you had national unity with the National Front present, you could say that we are united and the terrorists are isolated, but the problem is the infighting that starts the day after.”