The day before, as the event’s director, he was the chief organiser as hundreds of people gathered in front of the Trump Tower on Manhattan’s Fifth Avenue in a show of support for Donald Trump, the Republican party’s presidential candidate.

Trump endorsed the rally, posting almost a minute of footage of the event on Twitter while on the campaign trail in Arizona.

“So nice – great Americans outside Trump Tower right now. Thank you!” Trump tweeted.

Da Xia, the general organiser of the rally, declared it a great success.

“The rally was a perfect combination of Chinese ethics and Western democracy,” she said.

But Jia, 57, was not that happy with how things panned out the next day and was determined to make up for it.

“I will definitely do a photo on the Brooklyn Bridge again, on a better day,” he said.

Since migrating to New York in 2000, Dalian-born Jia had remained a political bystander until early this year.

Liang was the first New York City police officer convicted for a shooting while on duty in more than a decade. The Chinese community considered the court decision a result of racial discrimination.

“The Chinese community in New York formed a mutual aid society to support Liang and to defend our rights, and I was a board member of it,” Jia said.

Thousands of people from the Chinese community turned out to protest against the case in February. The demonstration did not prevent Liang from being sentenced but it did wake many up to the importance of political participation and activism.

And in a city with nine Chinatowns and an estimated 570,000-plus ethnic Chinese people, according to the 2014 American Community Survey, there is a sizable reserve of political power to harness.

Jia said he came up with the idea of organising an event for Trump in May after he became convinced that the Republican candidate’s policies would benefit Chinese Americans.

“I wanted to campaign for Trump as well as to create another chance to unite Chinese Americans,” he said. “But it’s really difficult organising a big event like this.”

Jia and a handful of friends contacted the Trump campaign and hammered out a coordination plan, joining forces with Italian American associations and other minorities.

New York is a strong Democratic Party state and many of the people brought together by the Liang case are loyal Hillary Clinton voters. Jia had to look for Trump supporters on social media like Facebook and WeChat groups.

“I posted my idea in some WeChat groups and was immediately kicked out,” he said.

He formed his own group, in turn kicking out people who made pro-Clinton comments.

Together, the group gathered at the Trump Tower rally on Saturday, making headlines in the Chinese language media and handing out hundreds of “Chinese Americans love Trump” T-shirts.

On Sunday, Jia called on all Chinese Trump supporters to put on the shirts and join a flash mob under the Statue of Liberty before moving on to the Brooklyn Bridge for photographs.

But fewer people turned up on time for the event and the handful of supporters who did end up taking the free ferry to the island got caught in the rain.

Jia later salvaged some pride by handing out shirts to a few young white men walking by, who expressed their support for Trump and took a photograph with his team.

“I don’t care about the result at the moment. I will just do my best to support Trump,” Jia said.

Packing up the last of the undamaged signs, Jia was determined to give it all another go.

“I will do it again. No matter how many people come,” he said.