New York business tycoon Michael Bloomberg has paved the way for a shot at the US presidency, registering as a candidate in the Alabama Democratic primary race before Friday's filing deadline.
Although the 77-year-old billionaire has not publicly announced his run, his inclusion among a crowded field kept his options open for mounting a concerted bid to topple a fellow New Yorker, President Donald Trump.
Analysts say a Bloomberg candidacy could do the most damage to the prospects of frontrunner Joe Biden, but the former vice president put on a brave face Friday and said he was not worried Bloomberg would draw away centrist voters.
Bloomberg's name was posted among 17 candidates on the Alabama Democratic Party's website only hours before registration closed.
Alabama is not one of the early primaries but it has the earliest deadline to register.
Biden, who will also turn 77 on November 20, has placed himself in the political center with South Bend Mayor Pete Buttigieg, while Vermont Senator Bernie Sanders and Massachusetts Senator Elizabeth Warren run to his left.
"Michael's a solid guy," Biden told reporters in Concord, New Hampshire, while registering to take part in the February primary in the northeastern state.
"I have no, no problem with him getting in the race," Biden said. "And in terms of he's running because of me, last polls I looked at I'm pretty far ahead.
"If I'm not mistaken I'm doing pretty well, both relative to Trump and relative to all the people running," he said.
Jason Mollica of American University said the entry of Bloomberg in the race could be "an indication that he believes the Democrats do not have a strong candidate that can defeat President Trump."
"Mr Biden's campaign isn't the strength it was at the start and if Mr Bloomberg gains the support of the centrists in the Democratic Party, that is a big sign for Mr Biden the party doesn't feel he's the right candidate, either," Mollica said.
Kyle Kondik of the Center for Politics at the University of Virginia said a Bloomberg run could conceivably draw support away from Biden but it remains to be seen how much backing he'll receive in a crowded field.
"At first blush, yes, one might think Bloomberg would hurt Biden more than others," Kondik said. "But we have to remember that sometimes voters don't fit neatly into ideological categories.
"While neither is running hard to the left and both are older white men, voters might perceive key differences between them," Kondik said. "Bloomberg has to actually show he can draw significant support in order to hurt Biden."
'Doesn't have the magic'
Trump weighed in Friday on a potential Bloomberg bid.
"Little Michael will fail," Trump told reporters in a reference to the stature of the 5ft, 8in (1.73m) Bloomberg. "He doesn't have the magic to do well.
"There's nobody I'd rather run against than little Michael," Trump added. "He's not going to do well but I think he's going to hurt Biden actually."
Bloomberg said back in March he wouldn't run but has been toying for weeks with the idea of seeking the White House after all, according to advisors.
"We now need to finish the job and ensure that Trump is defeated — but Mike is increasingly concerned that the current field of candidates is not well-positioned to do that," Bloomberg advisor Howard Wolfson said in a statement.
"Based on his record of accomplishment, leadership and his ability to bring people together to drive change, Mike would be able to take the fight to Trump and win," Wolfson added, according to Bloomberg News.
Bloomberg, co-founder and CEO of the media and financial information company that bears his name, is one of the richest people in the United States according to Forbes, worth $52.4 billion.
His huge personal wealth would likely shake up the contest at a time when Biden's fundraising is sagging.
Bloomberg, who was elected mayor of the Big Apple in 2001 and served until 2013, is seen as close to Wall Street and opposed to some of the policies espoused by the more liberal Warren and Sanders.
His entry would bloat an already crowded field of contenders, with 17 candidates vying for the right to take on Trump in November 2020 as the Democratic nominee.
Bloomberg has switched between the Republican and Democratic parties over the years and also served as an independent mayor.
He has used some of his fortune to back Democratic politicians and fund policies that he believes in — including gun control and the fight against climate change.
Bloomberg considered running for president as an independent in 2016 but eventually opted not to for fear of splitting the Democratic vote.