"Do I think Maduro is going to exit power eventually? Absolutely. Do I think he is going to do it willingly? I don't know. But a lot of that depends on the people holding him up," the senator said.
"Here's the bottom line: the rank and file military does not support Maduro, but they are not willing to face the very grave consequences of breaking with him."
These leaders, Rubio said, have the opportunity and responsibility to allow aid into the country.
"There are four or five senior military leaders, starting with the defense minister [Vladimir Padrino López], who if they were to recognize the interim government, that would be the end of the Maduro regime."
If military leaders recognize the interim government, Rubio told CNA, they could also benefit from amnesties offered by the interim government but "that window is closing, on them and on the country."
"The further this goes, the likelier it is that senior military leaders like [defense minister Vladimir] Padrino will disqualify themselves from the ability to receive domestic and international amnesty: because they deny food and medicine and thereby commit a crime against humanity; because they try to follow orders and attack unarmed protestors and civilians."
"It's in their hands, they can decide to change the trajectory of Venezuela."
In the meantime, protests continue in the country and, according to Rubio, the Venezuelan people "are well aware" that the Maduro and his loyalists stand between them and the flow of foreign aid into the country.
"There is no way, if current trends continue, that Maduro holds on to power," Rubio said. "The question becomes: how does he leave? Does he leave through a negotiated exit or does some other even occur that forces his hand?"
Earlier this week, Maduro issued a request for Pope Francis to act as a mediator in resolving the political standoff.
While the pope said that such a request for mediation would have to come from "both sides," Cardinal Baltazar Enrique Porras Cardozo, Apostolic Administrator of Caracas, appeared to pour cold water on the notion of papal intervention, telling Argentina's Radio Continental Feb. 6 that the suggestion was "non-viable."
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Rubio told CNA the request for papal mediation is a delaying tactic on the part of Maduro.
"He's already done this before, the Vatican tried to mediate [in 2016] and it was a fiasco - they walked away from it knowing that he wasn't sincere."
"Maduro has a very simple plan: to buy time until he can fracture the opposition and the world's attention is diverted to some other crisis and away from Venezuela."
"That's the model he has followed and he's trying to pull it off one more time."
The Venezuelan standoff began Jan. 10, when Maduro was inaugurated at the start of his second term. Both the National Assembly and the Venezuelan bishops' conference declared at that time Maduro's 2018 reelection to be invalid. Guaidó declared himself the nation's interim leader Jan. 23.
Rubio paid tribute to Guaidó and other opposition leaders in the country, noting the real dangers they face.