It’s a familiar story: a billionaire decides to cap a high-profile career with a bid for the the ultimate trophy position. The presidency.

But as Michael Bloomberg prepares to jump into the race for the Democratic nomination at a time when the party is energized by progressive politics, the shake-up he intends to perform on a fitful and crowded field may never come to pass.

The three-time New York mayor does not lack in attractive attributes, including pragmatic takes on climate change and gun control. But Bloomberg adviser Howard Wolfson did not set the political passions racing with his reasoning for his paymaster’s decision to start the process of registering in early voting states, beginning with Alabama on Friday.

“Mike believes Donald Trump represents an unprecedented threat to our nation,” Wolfson said. “Mike is increasingly concerned that the current field of candidates is not well positioned to do that.”

In short, the billionaire believes moderates in the Democratic party are suffering due to Joe Biden’s flagging campaign, and Biden’s fall could open the door to leftwing senators Elizabeth Warren or Bernie Sanders who, Bloomberg fears, will position the party too far left to unseat Trump.

Serious questions hang over any Bloomberg run. One school of thought reasons it may even boost the left wing he is seeking to trample.

With 2020 likely to turn on female voters – 51% of whom voted Trump in 2015 – one of many questions overhanging a Bloomberg candidacy is whether he can win women over.

He is also unlikely to be endorsed by any progressives – he has already crossed swords with firebrand New York congresswoman Alexandria Ocasio-Cortez over her campaign against Amazon situating a new HQ in New York and over the Green New Deal environmental policy.

At a time when Trump has been widely condemned by Democrats for his long record of insulting women and admission of sexual assault with his “grab them by the pussy” comment, Bloomberg faces his own problems. In 2008, his namesake financial-services and media company company was accused by at least 54 women of discrimination and sexual harassment – claims from a period after he left an active role in the company. He himself was not named in the suits.

Still, if Biden’s problem is money – at the last financial election filing he had just $9m on hand and was spending more than he was raising – Bloomberg would not have that issue. Recent surveys place his fortune at $51bn.

When the former mayor’s name last came up as a candidate, in February, top adviser Kevin Sheekey did not blanch at the calculation that Bloomberg would need to spend at least $500m to run a campaign.

“That’ll get us through the first few months,” Sheekey told Politico.

‘Another white billionaire’

Bloomberg’s name recognition may not be what he thinks it is, warned Alynna Lyon, a political scientist at the University of New Hampshire.

“His name may have resonance in the east,” she said, “but I’m not sure he is recognised in the south or the west and that could be a challenging area.”

In a 2016 poll that tested Bloomberg’s name recognition, about a third of voters said they had a neutral view of him and about a quarter said they were unsure of their impression or didn’t know his name. In the same poll, 27% said they had a negative view and just 16% of voters said they had a positive impression.

Timothy Hegle, a political professor at the University of Iowa, said Bloomberg’s candidacy could have the opposite effect of what he intends.

“If he enters, [it] could end up splitting votes for Biden, Buttigieg and Klobuchar – candidates trying to occupy the centre lane – and that ends up helping Sanders and Warren, and that seems to be contrary to his expectation.”

With less than 100 days to go before the Iowa caucuses, Democrats do not express dissatisfaction with their available candidates. Some 85% of the party’s primary voters said they were satisfied with the candidates, a Wall Street Journal/NBC News poll found late last month. Just 13% said they were unsatisfied.

That indicates that nerves over stuttering centrist candidates reflect a nervousness among the political elite, not actual party supporters.

Moreover the field is not lacking a wealthy white man. Voters have that in Tom Steyer, a Silicon Valley billionaire who has been running a well-financed campaign to little discernible effect.

“Steyer may have ruined it for Bloomberg, to a certain extent,” said Hegle. “Another white billionaire trying to buy the nomination is not going to change the race too much, and is not going to be well-received among activist Democrats. At best he’s going to split the centrist vote.”

For the time being, such arguments are academic. Bloomberg has not yet formally declared a run. He could still easily decide against the idea. Twice before, he has deferred to existing candidates for fear of splitting the vote. What’s different this time? Age, perhaps? At 77, he cannot plausibly wait another four years.

The prospect of a Bloomberg run does not seem to trouble Trump, who pitched in with a characteristically mean-spirited comment, telling reporters: “There is nobody I’d rather run against than little Michael.”

Much has yet to be determined but Hegle said: “It’s difficult to see his path to the nomination. He might potentially disrupt the race, and even then it’s hard to see how much disruption he can really create without an existing base of supporters.”