Rubio’s youth and inexperience, says an unaffiliated Republican strategist, are “obvious and very real” challenges, all the more so since Republicans have spent the past seven years scorning a president with the same qualities. But, says the strategist, Rubio “has an ability to speak clearly to the anxieties of voters and to articulate an energetic vision for the future. . . . If anyone has the political skills to overcome those kinds of critiques, it’s Rubio.”

Rubio’s team declined to respond to Bush’s remarks, but a Rubio ally tells National Review they are the product of increasing desperation on Bush’s part. “He’s worried about the poll numbers, he’s worried about the donor reactions. I don’t know that throwing a little elbow at him is going to make any difference,” says the ally.

Bush and his team are shrugging their shoulders about what is clearly a pivotal moment in the campaign. The governor, says spokesman Tim Miller, “was asked about the differences between his experiences and Marco’s. That’s what happens in a campaign!”