TORDESILLAS, SPAIN — Last week, I saw thousands of people chase and flee from a bull through the streets, past hundreds of screaming protesters, and into an open field where men on foot and horseback stabbed the animal to death.

I watched the riders return, armed with eight-foot-long steel-tipped spears. They rode past cheering locals and defiantly brushed up against a throng of animal welfare activists who hurled insults — “murderer,” “criminal,” “son of a b—-.”

Tordesillas, a rural town of 9,000, doubles in size during the infamous Toro de la Vega, as spectators gather to watch a bullfighting tournament that has occurred almost every year since medieval times. Over the past decade, however, protesters have shown up to denounce what they feel is the most shameful example of an anachronistic national tradition.

Thousands took to Twitter last Tuesday to condemn the festival. Using the bull’s name, the hashtag #RompesuelasVivo trended worldwide, and in Spain it was accompanied frequently by the phrase “ashamed to be Spanish.” Foreigners labeled the Iberian nation barbaric and “un-European” and asked how the event could survive in modern Spain.

Spanish support of bullfighting is at an all-time low, and this year, a number of local municipalities pulled public funding from bullfighting events, prompting several international media outlets to speculate that bullfighting is on its way out.

This is not the reality. Toro de la Vega shows just how resilient the tradition is, and a lack of political will among progressive parties means the bloodsport may continue indefinitely.

In this video released by Spanish political party PACMA (Animalist Party Against Mistreatment to Animals), a bull is killed during the Toro de la Vega. (PACMA TV)

Public support of bullfighting has waned. A poll conducted in 1995 by the Center for Sociological Research found 45 percent of respondents in favor of bullfighting. A Gallup poll in 2008 found 67 percent of Spaniards had no interest in bullfighting, while an Ipsos MORI poll commissioned by the Humane Society International in 2013 found only 29 percent of respondents supported the practice.

With Spain in the throes of economic turmoil, the number of events involving bulls fell from 3,651 in 2007 to 2,290 in 2011. It’s difficult, however, to find examples of events being prohibited specifically on animal welfare grounds.

Politicians from across the aisles have come out against Toro de la Vega. Many “aficionados,” or supporters of bullfighting, criticize the tournament for lacking the artistry and competition associated with the more well-known bull vs. matador arena spectacles. The last head of state who managed to temporarily ban the bull killings in Tordesillas was the dictator Francisco Franco, though he also promoted standard bullfighting events as the “fiesta nacional.”

Last week, the leader of Spain’s center-left Socialist Party, Pedro Sánchez, reiterated that he would end Toro de la Vega should he become prime minister, saying he feels “ashamed” when he sees images of the tournament. He took criticism, however, for not holding discussions with the mayor of Tordesillas — also a Socialist — about suspending this year’s tournament. He also made it clear last year that Toro de la Vega was a special case.

“I do not like bullfights, but I would never deny anyone the joy of watching José Tomás,” he said at a party convention, referring to a matador who has rock star status in Spain.

Parties to the left of the Socialists have also wavered over bullfighting. In its initial electoral program in 2014, newly formed left-wing party Podemos outlined its intent to “prohibit bullfighting” nationwide. The party received a shocking 8 percent of the national vote and became a legitimate political force just months after its formation. Podemos has since altered its stance, though: It now intends to initiate a slow “withering away” of bullfighting by pulling public funds for events at the local level.

Following municipal elections in May, several newly installed Podemos-backed mayors did just that, withholding amounts allocated for bullfighting events at publicly funded annual fiestas, fueling speculation that the slow death of bullfighting in some regions of Spain had finally begun.

On a local level, however, such amounts are modest — in the tens of thousands of euros. Diego Sánchez de la Cruz, financial journalist and co-founder of La Economia del Toro, an independent platform that conducts economic analysis of bullfighting, says the private sector is more than willing to pick up the slack.

“Private forces are very capable of sustaining this tradition with no need of public funds,” he told me, pointing to the example of La Coruña in the country’s northwest, where bullfighting events persisted via private resources after the suspension of public funds in 2012.

At the regional level, it’s much harder for the anti-bullfighting lobby to gain traction. The conservative Popular Party-led central government voted to attach “national cultural interest” status to bullfighting in 2013, granting the industry staunch legal protection.

This was a direct response to events in 2010, when Catalonia became the only region in mainland Spain to ban bullfighting. Most commentators agree the move had little to do with animal welfare and was motivated by a nationalist agenda, an attempt to further delineate a distinction between Catalan and Spanish cultural identity.

“Anti-bullfighting activists lobby politicians because they know that they will never be able to gather general support from the population,” de la Cruz said. “If you take a look at the political forces which have taken measures against bullfighting, you will see that the vast majority are populist, secessionist or radical parties.”

In 2010, a Metroscopia poll commissioned by Spanish newspaper El País found that while 60 percent of respondents did not like bullfighting, 57 percent also disagreed with Catalonia’s move to ban it.

Laws against animal cruelty that prohibit most bloodsports do exist in Spain, but bullfighting is generally not viewed as a sport. “Aficionados” consider it an art form intrinsically linked to Spanish cultural identity. In the arena, the matador does not “fight” a bull — he engages in a highly ritualized animal sacrifice. The arena is a portal through which spectators view generations of Spanish history — it’s as much about nostalgia and national identity as it is about entertainment.

Last year saw the first uptick in box office sales at bullfighting events since the financial crisis. Not coincidentally, it was also the first year with net job creation since the beginning of the crisis. Attendance at bullfighting events grew by 5 percent, and the total number of bullfighting events grew by 3 percent, according to Spanish financial journal Expansión. Figures from the Ministry of Education, Culture and Sport show the most represented age range at events in 2013 was 15- to 24-year-olds, dispelling the idea that the events only remain popular within an older, more conservative generation.

A survey by the think-tank Real Instituto El Cano suggests that flamenco, bulls and fiestas are the three things foreigners most associate with Spain. So for the government to ban bullfighting would be to erase part of the image Spain sells to tourists. It would be to amputate a part of Spain’s cultural identity and alienate a substantial minority within the electorate that sees bullfighting as sacred.

While some supporters of bullfighting draw a distinction between the arena shows and Toro de la Vega — the latter lacking highly skilled matadors — the outcome in both is the same. An animal is tormented, repeatedly wounded and finally slain. A ban on Toro de la Vega, which takes place in the heartland of conservative Spain, would set a worrying precedent for “aficionados.” They must take comfort from the evidence that those with power seem unwilling to take this first step.

For Silvia Barquero, president of Spain’s animal welfare party PACMA, the issue is simple: “If we don’t ban Toro de la Vega, Spain will continue to live in the past.”

Following the killing of Rompesuelas, I watched one horseman aggressively cut a path through the now hysterical hoard of protesters. He filmed them on his phone as he smiled and waved, willed on by thousands of his countrymen. The year’s drama was over, but the battle between progressive Spain and its conservative, traditional past has plenty of life in it.

With additional reporting by Sam Edwards