Inside the final hours of Bloomberg's presidential campaign

As the numbers ticked in on Super Tuesday night, the Bloomberg braintrust began to realize: things were’t looking so good. Worse than they could ever have imagined - and they had gamed out a lot of scenarios.

Campaign sources tell ABC News that when the evening began, and the wide swath of primary contests appeared unclaimed territory, the Bloomberg team expected to put some numbers on the board. Despite their late entry to the race, they had invested formidable ground game and dollars in the very delegate-rich states in play on Tuesday.

They hoped it would pay off. As the night wore on, their chances wore thin: each state’s returns, another blow to the chances the campaign would survive.

One of Bloomberg’s favorite sayings is, “In God we trust; everyone else, bring data.”

A senior aide tells ABC News, they began to look at the final numbers and saw there was no path forward.

As Wednesday dawned, campaign sources tell ABC News, staffers woke with a collective question: what were they still doing in? If the goal is to get rid of Trump - the focus and energy needs to be there.

Bloomberg called former Vice President Joe Biden that morning, the senior aide tells ABC News offering his unconditional support for the former vice president’s bid. He has long held respect for Biden, the aide says, and now, he wanted Biden to win.

At 11am, the Bloomberg team held a staff-wide call announcing what was a surprise to no one, according to the senior aide: Mike would be suspending his campaign.

Campaign manager Kevin Sheekey told his staff, they had run a great campaign and had a lot to be proud of.

Multiple campaign sources tell ABC News they had known for quite a few days that they were in trouble.

Bloomberg’s steady ascent in the polls had begun to face fierce headwinds - forced to face his record on stop and frisk, and past allegations of sexual harassment in his workplace.

His longtime team was well aware of the dangers posed by these fractious issues, campaign sources tell ABC News - but felt he would be able to overcome both. That calculation proved off at the Nevada Democratic debate - Bloomberg’s first in over a decade - where he was slammed from all sides of the stage by his 2020 rivals.

And there was never a chance to recover, the senior campaign aide tells ABC News. They had entered the race late and were chasing a truncated timeframe which ran right into Biden’s South Carolina firewall - and the coalescing of erstwhile centrist 2020 candidates around his chances.

Their slide from plateau to tailspin was so rapid, an aide said, it grew impossible to come back: campaigns may go up and down like stocks, the aide notes, and when you hit a “bear” market period, it takes time to recover. But the timing coming as it did - right before Bloomberg bet on winning big momentum Super Tuesday - marked the closing knell.

Bloomberg now throws his full weight behind the former vice president - and it’s sizable: he has pledged his vast resources to fuel the eventual Democratic nominee. The shape of what he does for Biden, however, remains to be seen; the senior aide tells ABC News they are in the midst of working through how to best deploy his operation’s force.

Staff morale is in a fair state, campaign sources tells ABC News, laughter still echoing in their open headquarters.

At some points, some have grown emotional remembering the work they had done on the campaign: one aide noted how proud they were of their policy around economic justice in black America - recalling how those people they met on the road were touched - that was meaningful to them.

Wednesday as he made his official exit, Bloomberg said in an emotional speech, he has “never believed in doing things halfway.” And though he’ll be bowing out his own bid now - he’ll still be fueling his “investment in beating Donald Trump.”

As he spoke, some staffers in the room were crying.

“Our campaign today for the presidency ends,” Bloomberg said. “But our campaign for a better America, a stronger America, a more just America, a more equal America and a more united America continues. And together, we will get it done.”

ABC News' Benjamin Siegel contributed to this report.