Indian anti-corruption activist Arvind Kejriwal addresses a press conference in New Delhi. (Saurabh Das/AP)

At a recent rally, supporters of an upstart Indian political party waved brooms in the air — a signal that they’re ready to clean house — danced in the dusty, sun-dappled street and chanted “End corruption!”

A clamor rose when the party’s leader, a slight man with glasses named Arvind Kejriwal, arrived in the back of an open sport-utility vehicle. As he greeted supporters, they pelted him with marigold blooms and chanted “Kejriwal! Kejriwal!”

Kejriwal, 45, was a little-known tax inspector-turned-activist just three years ago, before he spearheaded a series of hunger strikes and exposés of India’s rich and powerful that won widespread public support.

But now he faces his toughest challenge — turning that political goodwill into votes. His newly formed Aam Aadmi (Common Man) Party faces its first test in elections in the capital Wednesday, a run-up to national elections in the spring.

As his SUV crawled through the narrow streets of a working-class neighborhood of lumber shops and tiny stores, Kejriwal said he was elated by the response.

But reality kicked in when a TV news crew climbed on the vehicle’s running board and thrust a microphone in his face. News was breaking that candidates from Kejriwal’s party had been caught in a sting operation in which they appeared to welcome under-the-table donations.

“We are not disturbed about it,” Kejriwal said, after pledging to review the tapes and dismiss any candidates who acted improperly. But the incident was just the latest to show that Kejriwal’s shift from people’s icon to politician may be more difficult than expected.

Taking on culture of bribery

It has been two years since the India Against Corruption movement caught fire, prompting demonstrations in the streets of New Delhi and other cities. Middle-class residents were galvanized by several government corruption scandals and a growing sense of frustration over the bribes they had to pay in their own lives.

“Everything is costly. We have no proper lights, no proper sewage and no drinking water,” said Sushila Yadav, a 50-year-old schoolteacher from the western part of New Delhi who turned up to cheer on Kejriwal recently. “I don’t like paying bribes, but we are forced to.”

Kejriwal has been campaigning against corruption since his early days as a bureaucrat. But it was not until 2011, when he joined forces with another activist, Anna Hazare, that he received widespread attention.

Hazare, now 76, became the movement’s figurehead, a wise elder who clothed himself in Gandhian white and went on hunger strikes that captivated the country.

But the fevered excitement soon faded, and the men’s efforts to create a kind of corruption ombudsman for the nation ran into resistance in Parliament.

By this past summer, “it crystallized . . . that the parties and the whole system had gotten so corrupted that they were not going to yield unless they are seriously challenged in elections by honest people,” said Prashant Bhushan, a lawyer and co-founder of the Aam Aadmi Party.

Kejriwal and Hazare had a painful public parting of ways over the younger man’s decision to enter politics, and the two clashed again last month, when Hazare accused the AAP of unauthorized use of his name and likeness and questioned whether Kejriwal was misusing money from their civic movement. Kejriwal denied both accusations.

The AAP has promised free water and reduced electric bills, which critics say is calculated to get votes in this sprawling city of 16 million, where the government estimates that half the population lives in slums and illegal housing.

Kejriwal counts among his supporters teachers, small-business owners and many auto-rickshaw drivers, who have plastered AAP banners on the backs of their ubiquitous green-and-yellow three-wheeled vehicles. The party has received about $3.5 million in small donations — which it scrupulously notes on its Web site, an action rare in Indian politics.

AAP is fielding candidates for nearly all seats in New Delhi’s assembly, which is similar to a state government. Kejriwal himself is taking on Sheila Dikshit, the powerful three-term chief minister from the governing Indian National Congress party.

A recent poll on the assembly election by ABP News-Dainik Bhaskar-Nielsen found AAP in third place, with 23 percent, behind India’s two traditionally largest parties. Other polls have the AAP garnering far fewer seats.

The party has attracted much notice among Indian expatriates, and party chapters have formed around the globe.

“When AAP started talking about anti-corruption, transparency and reform, it resonated with a lot of people,” said Pran Kurup, 46, a native of India who heads an online learning company in California’s Silicon Valley. He was curled up on a foot-deep pile of marigolds in the back of Kejriwal’s campaign car recently, wearing a hoodie that evoked the style of Facebook founder Mark Zuckerberg. “Overall, the feeling among many expats who care deeply about India is that there is a need for systemic change and that systemic change can only be brought about by new players who are free of baggage.”

But even that overseas support has sparked criticism about Kejriwal’s party.

“They’re not capable of what they’ve been promising to do for the nation,” said Vineet Narain, a longtime journalist who has been an anti-corruption crusader. “These people are too ambitious, too immature and playing into the hands of Western interests.”

In a recent article in the Indian Express newspaper, columnist Shekhar Gupta argued that the reported sting operation that ensnared some AAP candidates put a long-overdue end to the fawning news coverage the party has received.

“For the first time now, they are having to ‘explain’ charges against them,” Gupta wrote. “So welcome to politics.”

Stigma of sting operation

The evening after news of the sting broke, Kejriwal arrived late to a gathering of more than 1,000 supporters — all wearing the party’s trademark peaked white caps, similar to that worn by independence leader Mohandas K. Gandhi.

The air was cool and smoky from smog and the veggie burgers and Tibetan dumplings being cooked in street stalls.

Kejriwal launched into a lengthy stemwinder, touching on his main campaign themes of corruption, rising food prices, women’s safety and the city’s water and power shortages.

He scarcely mentioned the reported sting operation conducted by journalists. The election commission is still evaluating the television footage, which AAP leaders say has been doctored. At the moment, it’s unclear whether the videos posted on — a news Web site run by a man who owns the country’s “first wedding entertainment channel” — amount to campaign dirty tricks — or corruption.

“I’m here in hope this new party, this guy Arvind Kejriwal, will do something different and good for us,” said Brijesh Kumar, a 21-year-old student at the rally. “I was shocked to watch that. It makes a difference about the way I feel about the party. We still don’t have the details. Kejriwal is a clean man, but there is a possibility those around him are not.

After the speech was over, people pressed forward to shake the candidate’s hand.

“When I see all the crowd, their expectations are so high, sometimes it becomes scary,” Kejriwal said, gesturing to the people with their white caps just like his, emblazoned with the words: “I am the common man.”

“But I think this is going to happen.”

Suhasini Raj contributed to this report.