Billionaire Mike Bloomberg last year decided to bet more than $500m on a political long shot.
The world's 12th richest person, Mr Bloomberg staked his millions on the idea that the Democrats would defy history and fail to elevate a front-runner after Iowa and New Hampshire's nominating contests.
Three months later, his jackpot is about to come due, as the former New York mayor, yet to appear on a ballot, emerges as a legitimate contender for the Democratic presidential nomination.
Bloomberg has benefited from a cascade of good luck - a botched and inconclusive Iowa caucuses process, the collapse of Joe Biden's polling dominance, and the Democratic Party chairman's decision to give him a path to the next debate.
His potential to reshape the race has led his Democratic opponents, as well as Donald Trump, to begin focusing on him in earnest, even though he is not contesting Nevada and South Carolina, the next two states to vote.
"You have a billionaire literally trying to buy an election and that's not the politics we believe in," said Ari Rabin-Havt, deputy campaign manager for Bernie Sanders.
Mr Sanders himself called Mr Bloomberg's self-funded candidacy "precisely what the corruption of the American political system is all about".
Fellow candidate Elizabeth Warren, the senator for Massachusetts, echoed that in a discussion with reporters on her campaign bus in New Hampshire. "Are we going to be in America where you've got to be a billionaire or suck up to billionaires to become the party's nominee?" she asked.
With the exception of Sanders, who finished strong in Iowa and won the New Hampshire primary, Bloomberg's rivals are heading toward the biggest voting day of the primary - Super Tuesday on March 3 - with no clear momentum.
Mr Biden and Ms Warren have been hobbled with two embarrassing losses.
Pete Buttigieg, the former mayor of South Bend, Indiana, and Minnesota senator Amy Klobuchar, who finished second and third in New Hampshire, face the challenge of winning over non-white voters who have not yet embraced their campaigns.
Mr Bloomberg, who has been dominating the airwaves unchallenged in many states, has said he does not want to engage directly with his rivals at the moment. He is not, however, above oblique references.
"We don't need a revolution. We want evolution," he told a mostly white crowd of hundreds at a rally in Tennessee, a nod to Mr Sanders and his radical policies.
"And we need a nominee who can deliver it."
Yet it became clear in recent days that the scrutiny is coming from all directions.
As New Hampshire voters went to the polls, the Biden campaign joined with President Trump in trying to spread around a 2015 audio clip in which Mr Bloomberg defended the targeted frisking of black and Latino New Yorkers during his time as mayor.
It is a policy he has since renounced and apologised for promoting.
"95pc of your murders, murderers and murder victims fit one MO," he was recorded as saying at an Aspen Institute event.
"You can just take the description, Xerox it and pass it out to all the cops."