Diaz, the hard-charging operative who was brought on as Bush’s campaign manager in the spring, said the campaign is now assertively taking Trump on because it views the billionaire businessman as a “legitimate” threat.

“Mr. Trump is in this for the long haul,” Diaz said. “I think that’s abundantly clear. I think it’s also clear that he intends to run a legitimate campaign.”

The Bush team is trying to sow doubts among conservatives about Trump’s ideology by casting him as a liberal interloper. The critique was designed not merely to damage Trump but also to let movement conservatives see Bush speaking from a position of relative purity. The attacks will continue, with the help of big-name surrogates.
In the interview, Diaz challenged the media to adopt a more aggressive tone covering Trump, as it would any other front-running candidate.

“He should be asked serious questions to see if he can offer serious responses,” he said. “I think it’s totally in question whether he’s capable of doing that.”