A leaked campaign playbook for Republican presidential hopeful Jeb Bush has revealed a strategy that counts on denigrating rival Marco Rubio and calming donors about their beleaguered candidate’s weak performance on the trail.

“Marco is a GOP Obama” and the “press obsession” with the debates does not matter, Bush donors were told by the campaign in a PowerPoint presentation leaked to some outlets and a 112-page file acquired in full by the website US News and World Report.

Bush, the former governor of Florida, once treated Rubio, currently senator for the state, as his greatest disciple, shepherding the younger man’s ascent through Florida politics and forming a close friendship with him, even passing him a ceremonial sword when Rubio was sworn in as speaker of the Florida house of representatives. But the mutual admiration has been replaced by an acrimony that was exposed on national TV during Wednesday’s Republican debate, when the men sniped at each other over politics.

Three slides are devoted entirely to disparaging Rubio, beginning with the title: “Marco is a risky bet.”

One slide alludes to apparent skeletons found in Rubio’s closet, saying: “Those who have looked into Marco’s background in the past have been concerned with what they found there.”

A Bush aide told US News that the line refers to something found by the team of 2012 nominee Mitt Romney when they vetted Rubio for vice-president, but the former Romney adviser Beth Myers denied any such concerns.

“As the person who handled the VP vetting for the Romney campaign, I saw all the vetting documents,” Myers said. “Senator Rubio ‘passed’ our vetting process, and nothing we found would have disqualified him from serving as VP.”

The presentation goes to great lengths to downplay the former Florida governor’s steady descent in the polls, where he has fallen into single digits behind Donald Trump, Ben Carson and Rubio. Bush’s aides tried to reassure donors that reports of his “death spiral” campaign were overblown in this early stage of the race, and compared the primary election to previous cycles, when ultra-conservative Rick Santorum and pizza mogul Herman Cain led the polls.

In 2012, Romney, the eventual Republican nominee, came in a close second in the Iowa caucuses to Santorum, behind by only 34 votes.

Bush’s aides even suggested that voters flit between choices because they suffer from attention deficit disorder, writing that the “race will remain fluid for some time because … voters have ADD”.

Backlash to a similarly belittling comment posted to Trump’s Twitter account forced the billionaire to make the approximation of an apology. He blamed a “young intern” for the tweet, which suggested Iowa voters have “issues in the brain”.

The presentation promised that Bush would outlast the “carousel of frontrunners”, even though his status as presumptive nominee has faded during his campaign struggles. In Iowa for instance, staffers have made 70,000 phone calls but identified only 1,281 known supporters.

The presentation makes clear that Bush does not fear Trump and Carson, the current frontrunners, nearly as much as he worries Rubio will steal his supporters and eventually the party’s nomination.

Other slides accuse the Florida senator of inexperience, saying “outside of lobbying and legal consulting, no credible experience beyond government”, and “never been in charge of anything larger than two dozen people”.

Bush’s campaign also says Rubio is guilty of “misuse of state party credit cards, taxpayer funds, and ties to scandal-tarred former Congressman David Rivera.” While working in the Florida state house, Rubio charged grocery bills, car repairs and liquor store purchases to the party. In 2005, he bought a house with Rivera, a state lawmaker charged with numerous ethics violations.

During Wednesday’s presidential debate, Rubio deflected a question about his finances by saying it amounted to a “litany of discredited attacks” – a departure from his memoir, when he confessed a “lack of bookkeeping skills”.

“I didn’t inherit any money,” Rubio said at the Republican debate. “I had to save money to go to school, I had to borrow money to go to school.”

During the debate, Bush attempted to use Rubio’s record against him, criticizing the younger man for having the worst voting record in the Senate: “You get, like, three days where you have to show up? You can campaign, or just resign and let someone else take the job.”

Rubio turned the attack against Bush, who was seen as his mentor while both worked in Florida. “Someone has convinced you that attacking me is going to help you,” he told Bush. “My campaign is going to be about the future of America, it’s not going to be about attacking anyone else on this stage.”

A third slide frames Rubio as anathema to conservatives: a senator with too much in common with Barack Obama to make Republicans comfortable.

“Rubio and President Obama have strikingly similar profiles,” the slide reads, saying they “had few legislative accomplishments and haven’t shown much interest in the process of advancing legislation and getting results”.

The Rubio campaign did not respond to requests for comment.

The personal attacks against Rubio, the only Republican candidate highlighted this way, are nestled among pages of internal polling data, advertising plans and talking points to spin.

Aides searched for silver linings in details like how “48% of those currently not voting for Bush say they ‘could support him for president’,” and told donors that the real push would begin next year with a nearly $11m advertising plan.

Bush apparently also intends to woo young people and minority groups, typically not conservative voters. The presentation includes an ad called “Denisha”, about a black student who used Bush’s voucher school program, and a “Jeb TV” audio segment titled “#JebNoFilter: Sharknado 3”, a reference to the comedy-horror film franchise about sharks cast flying on to land by strong winds.

Additional reporting by Sabrina Siddiqui