There is a popular video on YouTube, viewed more than one million times, showing a group of hapless financial regulators squirming under questioning by Massachusetts senator Elizabeth Warren.

At her first congressional banking committee hearing in February since winning a Senate seat last year, Warren grilled big-bank regulators on why they had never taken a Wall Street giant to court.

“There are districts attorneys and US attorneys who are out there every day squeezing ordinary citizens on sometimes very thin grounds and taking them to trial in order to make an example, as they put it,” she told them. “I am really concerned that too big to fail has become too big for trial.”

The Democratic senator’s attacks on the recovering influence of Wall Street, surging student debt, consumer protection and the deepening divide between the rich and working classes in the US have invigorated the party’s core supporters and raised hopes that she might run for president in 2016.

Although Warren herself has ruled out presidential bid – and running against the might of Hillary Clinton’s political machine and broad appeal is generally viewed as career suicide – the straight-talking class warrior has stoked key Democratic constituents on the left, in the labour movement and beyond, so much so that she is considered a natural heir to the populist liberal agenda spawned by US president Barack Obama.

The former Harvard professor of bankruptcy law, who helped create the US Consumer Financial Protection Bureau, ticks many boxes for presidential material among Democrats who fear Clinton’s centrist economic stance and cosiness with Wall Street, a font of fundraising loot for the former secretary of state.

Warren has lived through the inequalities against which she rails. Her father suffered a heart attack when she was 12, leaving the family struggling to pay medical bills and loans.

To make ends meet, her mother found work in Sears department store, while Warren worked in her aunt’s Mexican restaurant.

Along with being a woman, a big help in the 2016 race, Warren is a media darling, thanks to her high-profile congressional interrogations on inaction in financial regulation.

A thoughtful and passionate advocate, she can articulate the popular sentiments of groups such as the Occupy movement into a compelling David v Goliath message of protecting hard-working families against big vested interests.

“Her strengths are that she really, really knows and understands her issues and she comes off as extremely authentic,” says political strategist Chris Lehane, a former adviser to Bill Clinton.

“She has demonstrated the courage to take on powerful interests and has the capacity to take complex ideas and boil them down in ways people can understand without dumbing down the conversation.”

Warren’s growing power was seen last summer when she and fellow Democratic senators Sherrod Brown and Jeff Merkley campaigned successfully to block the appointment of Larry Summers, an early proponent of the deregulation that fuelled the financial crisis, as chairman of the US Federal Reserve.

Democrat Bill de Blasio’s victory to become New York mayor this month – won on a platform, similar to Warren’s, of easing income disparities in the city – shows the popularity of the message.

“Imagine it’s January 2017 and Elizabeth Warren is president – that is a very frightening scenario,” a Wall Street financier says. “Her charisma, her intelligence and her ability to connect with people and to articulate a view that is stridently opposed to big business – it is a very frightening vista.”

While her anti-big-business stance is unlikely to land her donations on Wall Street, Warren has shown capacity to draw funding. The $42 million (€31 million) out-of-proportion haul for her Senate race, half of which were online donations, shows her capacity to mobilise widespread support.

One Democratic aide observed that a left-wing candidate such as Warren faced the same problem as candidates on the Republican right: they might win a primary or local election but they are not centrally aligned enough to win over a much broader appeal at a national level.

A Warren run would pull mainstream Democrats and Hillary Clinton towards the left, potentially leaving space for a moderate Republican to exploit, a fate that befell Democrat George McGovern in 1972.

As the financier puts it: “Would Warren create an opportunity for a party that is on its ass?”

Democrat voters have moved closer to Warren’s outlook. Gallup found that since 2007, the number of Democrats with “very negative” views of the banking industry rose more than fivefold, while the percentage dissatisfied with the “size and influence of major corporations” rose from 51 to 79. This poses problems for Clinton among the grassroots given her big-business donors.

Warren is clearly aware of Clinton’s strong position, but she may yet run for another reason. “She is potentially strategically looking to lever the mere prospect of a possible run to help generate more interest in her agenda and shape the Democratic Party’s approach and philosophy when it comes to taking on the issue of economic inequality in a robust and aggressive way,” Lehane says.