Marco Rubio, 2016's great neocon hope

“Whereas Rubio clearly has some views that he has considered and articulated, my sense of Cruz is that he is much less formed by conviction,” says one foreign-policy expert who has met with both potential candidates. “His background was really more on the domestic side.”

Cruz has repeatedly said he embraces a Reaganite foreign policy. He made headlines in recent weeks for walking out of an event when a group of Arab Christians booed his vocal defense of Israel, and he has used his seat on the Armed Services Committee to travel abroad during his time in office. But those I spoke with were, across the board, unimpressed. They universally characterized his worldview as shallow, opportunistic, and ever shifting to where he perceives the base of the party to be.

A former senior Bush administration defense official criticized the Texas senator in particular for his failure, as a member of the Armed Services Committee, to advocate for raising the defense budget. “He’s basically not done anything that I’m aware of to put an end to the hemorrhaging in the defense department, so it rings a little hollow,” he says. “It’s one thing to posture, it’s another thing to have a consistent policy. That doesn’t mean he couldn’t develop one. I don’t want to write him up as a lost cause, but he has a long way to go before he could be considered on the same bar as Rubio, considered to have a coherent world view.”