Seven have so far announced their forthcoming campaigns, with senators Elizabeth Warren, Kamala Harris and Kirsten Gillibrand among the most prominent and other party grandees expected to follow suit.
Many more from outside the political establishment have declared their intention to run and among the most interesting of these is entrepreneur Andrew Yang.
The would-be president warns the automation of labour places a third of all American jobs under threat, his first campaign video opening on a bleak vision of post-industrial decline, and believes the answer is universal basic income, proposing to give every American aged between 18 and 64 $1,000 (£775) a month, a policy he calls the “Freedom Dividend”.
“All you need is self-driving cars to destabilise society,” Mr Yang told Kevin Roose of The New York Times last year.
“We’re going to have a million truck drivers out of work who are 94 per cent male, with an average level of education of high school or one year of college.
“That one innovation will be enough to create riots in the street. And we’re about to do the same thing to retail workers, call centre workers, fast food workers, insurance companies, accounting firms.”
As pessimistic as that statement might sound, Mr Yang, 44, cannot be accused of lacking vision and deserves credit for criticising developments often unthinkingly accepted as tokens of progress.
A native of Schenectady, upstate New York, he is the son of Taiwanese immigrants: his father a researcher at IBM and General Electric responsible for 69 patent applications; his mother a university systems administrator.
He describes his upbringing as “pretty nerdy”.
After graduating in economics from Brown University and later from Columbia Law School, Mr Yang briefly worked as a corporate attorney before changing tack to found a charitable start-up that folded in 2001 with the bursting of the first dotcom bubble.
Moving on to healthcare software company MMF Systems, he subsequently joined his friend Zeke Vanderhoek’s educational support company Manhattan Prep, serving as its CEO until the company was acquired by Kaplan in 2009, making his fortune.
His next undertaking was Venture for America, which connected recent graduates with start-up businesses, a project that saw him travel the country and see the impact of automation on employment at close quarters, a phenomenon he says explains the rise of Trumpian populism.
“The reason Donald Trump was elected was that we automated away 4m manufacturing jobs in Michigan, Ohio, Pennsylvania and Wisconsin,” Mr Yang told The Times.
“If you look at the voter data, it shows that the higher the level of concentration of manufacturing robots in a district, the more that district voted for Trump.”
His “Humanity First” platform could be well-timed to capitalise on anti-tech sentiment, with Facebook and Twitter facing greater scrutinty than ever before over their vulnerability to manipulation and concerns growing about how much time people, particularly children and teenagers, spend glued to their smartphones.
Critics of universal basic income, which Mr Yang proposes to finance by taxing the tech giants, argue the policy is too expensive to be realistic. Paying every elligible American citizen $12,000 (£9,300) a year would cost an estimated $2 trillion (£1.5 trillion), roughly half of the annual federal budget.
But the New Yorker insists the scheme is viable and, to prove it, chose a family in New Hampshire as a test case.
In what sounds like the premise of a 1930s screwball comedy from Preston Sturges or Frank Capra, Mr Yang handed his first cheque for $1,000 to Charles Fassi at a New Year’s Eve party – the recepient having lost his job at a chemical equipment manufacturer four months earlier - in order to prove his Freedom Dividend was the way to help struggling families.
“The goal is to illustrate the impact $1,000 a month can have on a family or a household here in New Hampshire and putting my money where my mouth is,” Mr Yang told New Hampshire Public Radio.
The draw of universal basic income is significant – Bernie Sanders, Mark Zuckerberg and Elon Musk endorse it and Hillary Clinton toyed with the idea in 2016 – but Mr Yang remains a longshot for the Democratic nomination.
He has some other interesting ideas, notably appointing a White House psychologist, making 15 April a national holiday to “make tax fun” and establishing a Department of the Attention Economy to monitor social media usage, the latter outlined in his book The War on Normal People (2018).
His campaign is still at an early stage, however. His website is currently relatively sparse, with only one item listed under “Fun Stuff”, the chance to have a dim sum lunch with the candidate at the TimHoWan restaurant in Hell’s Kitchen, New York City.
Taking him up on the offer would costs you a $1,000 donation, which, if he were to realise his vision for America, would clean out your entire month’s salary from the government.