As of today, the group had raced through at least US$95.7 million out of the US$118.6 million it had collected by the end of January, according to Federal Election Commission filings.
Almost US$87 million went into a barrage of television ads, online videos, slick mailers and voter phone calls. The group flew an airplane with a banner mocking Donald Trump over a rally of his supporters, produced a 15-minute documentary detailing Bush's biography, sent Bush supporters individual video players, took out a billboard mocking Trump and crammed the airwaves in Iowa, New Hampshire and South Carolina.
To no avail. Bush's favourable rating actually plummeted over the course of the campaign, falling from 63 per cent in July to 44 per cent in January, according to Washington Post-ABC News polls of Republicans nationally.
The super PAC's failure to help Bush gain traction will be one of the most scrutinised aspects of his failed candidacy, in part because he built his strategy around having the well-funded group by his side. The former governor installed his long-time adviser Mike Murphy at its helm, and spent the first half of last year helping sock millions of dollars into the super PAC - all while maintaining he had still not decided to run.
"You might as well frontload it if you can," Bush said last year.
Murphy, meanwhile, expressed confidence that the super PAC's financial might would be overpowering. "Our job is just to amplify his story and what he's saying and we banked enough cash that nobody's turning our speaker off," he told Bloomberg in October.
As Bush failed to gain traction, the super PAC's donations dried up. It still had US$24.4 million at the end of January, but collected just US$370,000 that month. The majority, US$250,000, was donated by Michigan businessman and Orlando Magic basketball team owner Richard DeVos.
DeVos was already looking elsewhere, however. On the same day, he gave another US$250,000 to a super PAC allied with Senator Marco Rubio of Florida.
A family affair
At the start of the presidential race, the smart money was on Bush to become the third member of the family to enter the White House, following in the footsteps of his father George HW Bush and his brother George W Bush.
But as the battle turned nasty, it seemed as if he had little spirit for the fight.
Having tried to prove he was "his own man", Bush appeared to distance himself from his family.
Indeed his mother, Barbara, said in April 2013 that the US had had enough Bushes in the White House.
But then in what to some seemed a sign of desperation he persuaded the 90-year-old former First Lady to stump for him first in New Hampshire and then in South Carolina.
Then his older brother, George W turned on the folksy charm.
But it was all to no avail.
Bush said he hoped to contribute to the conservative cause as a private citizen. Time will tell whether this ends a political dynasty which dates back to his grandfather, Prescott Bush, the family patriarch who served as US senator for Connecticut.
It will now fall to Jeb Bush's son, George P Bush, Texas Land Commissioner, to decide how far he wants to go in the family business.