Just a few years ago, Pablo Iglesias was an obscure political science lecturer at a Madrid university who fit in with its reputation as a hotbed for radicals. The onetime communist from a working class neighborhood even traveled to Venezuela and Bolivia to train left-wing government officials in topics like "the ascent and future decadence of the world capitalist system."

Then something happened that changed his life and Spanish politics: The hard-left Podemos party the ponytailed professor co-founded last year became a surprise winner of seats in the European Parliament — just a few months after it was formed. Buoyed by growing momentum driven by rage against austerity, Iglesias is now poised to lead the party into Spain's Parliament and disrupt its historical order.

Iglesias and Podemos ("We Can") are robbing support for Spain's center-left Socialist Party and threatening — along with another renegade party — to shatter Spain's traditional two-party system. The Socialists have alternated power with the ruling conservative Popular Party, led by Prime Minister Mariano Rajoy, since the 1970s.

"A majority of the citizens are convinced that we're governed by corrupt thieves, and they want fresh air and some changes," Iglesias told The Associated Press in an interview at his sparse startup-style Madrid office, featuring a poster of revolutionary icon Che Guevera. "That is exactly why Podemos works."

The main question is how much Podemos and the centrist Ciudadanos (Citizens) party will truly shake up the status quo — and which one will turn out to be the likely kingmaker in Spain's emerging four-party system. Spain's Dec. 20 election follows the triumph of the far-left Syriza, a Podemos ally, in Greek elections and the shock anointment last month of Jeremy Corbyn, a Socialist warhorse, as leader of Britain's Labour Party.

Polls show Rajoy's Popular Party leading slightly but far short of winning the absolute majority it has enjoyed since a 2011 landslide victory over the Socialists. That means the Popular Party would need to find an ally, most likely Ciudadanos, to form a government. Another possibility would be for the Socialists and Podemos to try to team up to lead the country.

Unpopular austerity measures imposed by the Popular Party are credited with helping to prevent Spain's economy from crashing, then aiding an economic recovery. But unemployment stands at 21 percent — and voters are enraged over seemingly endless corruption scandals hitting members and ex-members of the Popular and Socialist parties.

Iglesias and Podemos activists call their mainstream political foes the "caste." They see the Popular Party and Socialists as partners in crime supporting "neo-liberalism," their term for a mix of unfettered free-market economics and liberal global trade. According to them, it benefits rich countries and corporations but hurts the working class and poor.

In Spain, Iglesias says, the entrenched political elite on the right and left who embraced neo-liberalism are to blame for setting the country on a real-estate driven boom that eventually went bust amid the financial crisis, and left banks with so much toxic debt they had to be bailed out. The deal with Europe and international institutions for the bailout money came in return for higher taxes and cuts to cherished worker benefits, national health care and education.

Podemos wants to roll back the cuts, reduce the working week from 40 hours to 35, study the re-nationalization of large companies privatized years ago and grant subsidies to low-paid workers so they'll make at least 900 euros ($1,000) per month. Also proposed is a restructuring of private debt held by ordinary people and small businesses, as well as Spain's public debt — which is expected to hit 100 percent of the country's annual economic output by the end of this year.

The party would pay for the increased costs by hiking taxes on rich Spaniards and big Spanish companies, along with allowing Spain's deficit to grow. That spooks Spanish business leaders and affluent voters, and experts say the re-nationalizations and deficit increase would go against rules Spain agreed to as part of its membership of the 19-nation group using the common euro currency.

But Iglesias defends the moves as logical wealth redistribution, similar to Nordic countries where citizens pay some of the world's highest taxes but enjoy extensive social benefits.

"It's great that we have rich people, but for the rich to be rich, the key is not to impoverish the rest of the country," Iglesias told the AP. "The most efficient countries, the best places to do business, are the least unequal and most prosperous countries."

He doesn't worry about angering German Chancellor Angela Merkel or other European leaders seen by many Spaniards as responsible for forcing the country into austerity.

"Francois Hollande (France's president) is a vice chancellor to Mrs. Merkel, the same way that Rajoy seems like an administrator of a European province, and we can't have that," Iglesias said.

If elected, Iglesias said he would be respectful toward Merkel but would tell her point blank: "We're not going to be your province. We're going to be a sovereign nation, just like yours."

Iglesias' party made history in May when Madrid and Barcelona swore in leftist mayors backed by Podemos in one of Spain's most significant political upheavals in recent memory.

Retired judge Manuela Carmena and anti-eviction activist Ada Colau cut their own mayoral salaries, and have taken steps to try to halt evictions of crisis-hit homeowners — who must still repay much of what they owe after losing foreclosed homes. They have also promised to eliminate perks enjoyed by the rich and famous.

Podemos was rivaling the No. 1 Popular Party and second-place Socialist Party in popularity early this year, but has since seen its support drop. It is now in fourth place after Ciudadanos.

Iglesias says opinion polls are fluid and party popularity can change quickly. But analysts say Podemos failed to shore up support by refusing to merge with a smaller far-left party and erred by softening some stands to lure centrist voter support.

"It's clear that there are two currents in Podemos," said Antonio Barroso, a London-based analyst with the Teneo Intelligence political risk consultancy. "One that wants to get closer to the center and one that wants to stay on the left. And Spaniards don't like divided parties."

Much of the party's strength rides on Iglesias, who is renowned for a natural TV media presence honed through years of appearances on Spanish political talk shows. He dresses in jeans, plaid shirts and a black hoodie — the antithesis of Spain's traditional male politicians in expensive suits and ties.

Iglesias' ponytail is one of his biggest assets, because it makes him recognizable like Winston Churchill with his cigar, said Felicisimo Valbuena, a political communication expert and retired professor at the Complutense University of Madrid.

Some politicians and commentators made a big mistake by ridiculing Iglesias' ponytail when he was launching Podemos last year, Valbuena said.

"They were laughing at him, and that was the biggest favor they could have done for him," he said. "It was pure propaganda in his favor."