In a PowerPoint presentation, delivered at a donor retreat in Houston, Bush advisers sought to calm concerns about his campaign by highlighting his advantages in money, endorsements and data over his GOP rivals.
It highlighted polls making the electability argument for Bush, showing him ahead of Hillary Clinton in a hypothetical match-up, and it gave details on the strength of his ground game in the early states.
But a big goal of the presentation was to compare Bush's campaign to his primary opponents, and it was no happenstance that Rubio specifically was the subject of several bullet points.
Despite the current voter fervor for anti-establishment candidates, Bush's team believes it's important to focus on Bush's record as a two-term governor of Florida, arguing that his tenure shows an aptitude of "fixing" things in government.
In a slide titled "Experience Matters," one bullet point reads:"Marco is a GOP Obama."
Both ran for president as first-term senators, were lawyers and university lecturers, had served part time in state legislatures for eight years, and had "few legislative accomplishments," the slide said.
Another slide is entirely dedicated to pointing out the advantage Bush holds in endorsements over Rubio (Bush has 11 endorsements from Florida's congressional delegation, Rubio has one), while another compares the campaigns' cash-on-hand numbers, with Bush having slightly more in the bank.
Later Monday, Bush himself took a swipe at Rubio. In an on-stage conversation with his brother, former President George W. Bush, Jeb Bush boasted about how he "vetoed a couple of projects for one of the presidential candidates," referring to when Rubio was in the Florida House of Representatives when Bush was the governor.
Tensions between the two candidates have been escalating for weeks. With reports of Rubio missing nearly one-third of his votes
in the Senate this year, Bush has been hammering lawmakers who aren't doing their jobs, and late last month he started comparing Rubio to Obama's lack of experience before becoming president.
In 2012, however, Bush told Charlie Rose that he thought Rubio would be the best running mate pick for Mitt Romney.
"He has more experience than Barack Obama had when he ran," Bush had said.
Pressed on those comments earlier this month in Iowa, Bush stuck by them.
"Yeah, he did (have more experience than Obama). He still does, that's for sure," Bush said. "That's a low bar, though."
For his part, Rubio hasn't been quite as direct in his comments about Bush on the campaign trail, but he regularly calls for a "new generation" of leadership, a subtle dig that many see as an attack against Bush and Democratic front-runner Hillary Clinton.
Despite the thickening competition, the two candidates publicly maintain that they've stayed friends.
As for the rest of the presentation, which came just days after the campaign announced it was downsizing its staff and slashing salaries, Bush advisers believe that the "press obsession with process" won't determine the outcome of the primary. They're laser-focused on the idea that as long as Bush has the cash, discipline and organization, he can push through.
In single digits, and frustrated by the Trump phenomenon, Bush's campaign is "tearing up the script" and going to "Let Jeb be Jeb." Sources close to the campaign say the campaign has realized they have "nothing to lose" and they are going to take a new tack of letting Bush relax and speak his mind.
In the presentation, they included a breakdown of the number of staffers and offices the campaign has in each early state: South Carolina: seven paid staffers and three offices; Nevada: eight paid staffers and two offices; New Hampshire: 12 paid staffers and one office; Iowa: 10 paid staffers and two offices.