He's been labeled the French Fidel Castro, but his mentor in politics is the late French President Francois Mitterrand. A radical Trotskyist in his youth, he's also served as a minister in a Socialist government.

It took Jean-Luc Melenchon a long time to find his own way in politics.

Now at the peak of his popularity, the far-left French presidential candidate is the new face of French populism, embodying the fight against austerity politics in the European Union, where he feels that money — not people — is its driving force.

"The error is not the worker," Melenchon often says. "The dough is the error."

The 65-year-old is running for president for the second consecutive time after finishing in fourth place five years ago with 11 percent of the vote. This year, Melenchon's debating skills, anti-capitalist rhetoric, pugnacity and grasp of social issues have seen him surge in the campaign's closing stages.

French voters cast ballots Sunday in the first round of the country's presidential election. The top-two vote-getters there move on to a presidential runoff vote on May 7.

In the face of France's chronic high unemployment — which now stands at 10 percent — Melenchon's appeals to the working class have struck a chord. After five years of Socialist Francois Hollande's presidency, voters appear to be abandoning Socialist contender Benoit Hamon, with many switching to Melenchon, who left the Socialists to found the Left Party.

Melenchon promises to tax the rich and spend heavily, to renegotiate France's role in the 28-nation EU and international trade pacts. He also wants to get rid of what he calls the "presidential monarchy" by giving more power to parliament, and to stop France's use of nuclear power, the source of nearly 80 percent of the country's electricity.

Renowned for his temper tantrums against journalists, the former Socialist senator is described by opponents as a dangerous, angry and irresponsible autocrat.

"You need to kick the doors open. This is the meaning of anger," says Melenchon, who is backed by the Communist Party.

Another Melenchon trademark: a little red triangle he wears on his jackets, worn by political prisoners in Nazi concentration camps during World War II. Melenchon says it differentiates him from far-right presidential candidate Marine Le Pen — his political nemesis — after critics likened his platform to hers.

Their sharpest difference is on migrants. Le Pen wants to staunch their flow into France while Melenchon says they need to be welcomed humanely. At one rally by the sparkling Mediterranean Sea, Melenchon held a moment of silence for the thousands of migrants who have drowned while trying to cross it.

"Listen: It's the silence of death," he told the crowd.

Melenchon distanced himself from Le Pen again following the shooting of Paris police officers on Friday night. While Le Pen urged the government to restore France's borders immediately, Melenchon said France should not give in to panic.

"Our duty as citizens is to stay away from the polemics our enemies are dreaming of, and, on the opposite, to stay together," Melenchon said.

Born in Tangiers, Morocco, from parents of Spanish and Italian origins, Melenchon started his political life with the Trotskyist movement OCI before joining the Socialist Party in the late 1970's.

After becoming the youngest French senator ever, he also served as minister for vocational training under Prime Minister Lionel Jospin. Deeply shocked by Jospin's elimination in the first round of the 2002 presidential election, when far-right leader Jean-Marie Le Pen, father of Marine, went through to face Jacques Chirac, Melenchon bounced back three years later during the campaign against EU's proposed constitution.

Rejuvenated by the "no" vote at that referendum, Melenchon, however, failed to impose his leftist views and left the Socialist Party.

Melenchon's platform has not changed much from 2012 but he has toned down a bit. French tricolor banners have replaced the seas of red Communist flags at his gigantic rallies. His supporters now sing the French national anthem instead of L'Internationale.

Criticized by some as a man of the past, Melenchon has still exceled in mastering new technologies. His Twitter account has more than 1 million followers. His YouTube channel is popular and his use of holograms at rallies to appear simultaneously in multiple venues has attracted headlines.

"We are inextinguishable, nobody and nothing can finish us off," Melenchon said. "All you need is an ember to ignite the prairie."