On Sunday President Donald Trump raised new questions on the political fate of Defense Secretary Jim Mattis when he told ’60 Minutes’ journalist Lesley Stahl that he thinks the career military officer may be “some sort of Democrat."

The comment raised new questions about Mattis’ future in the Pentagon’s top job: Was this the kiss of death for Trump’s favored general?

“Not necessarily,” said Jim Carafano, a national security expert at the conservative think-tank The Heritage Foundation.

“By and large on most national security matters Mattis isn’t far off base from where the president is,” he said.

Mattis spent more than 40 years in the Marine Corps where his political views were not widely shared. But his oft-quoted hawkish remarks on war and conflict were likely interpreted as benchmark conservative, Carafano said. And on some of Trump’s more controversial social initiatives, such as the Defense Department’s transgender policy, Mattis’ views on military operational needs have aligned with the president’s personal views.

Where Trump has been frustrated with the Pentagon’s leadership — such as slow-rolling on things like his desired military parade, or a potentially differing view on the NATO alliance, or the creation of a space force — the friction may not be a reflection of Mattis' politics but rather a reflection that Washington doesn’t work like a Trump corporation, Carafano said.

Each agency has years of alliances, staff who have known and worked with each other for decades, and invested personnel whose Congressional budgets and legislative agendas do maintain some independence from the White House.

“In the corporate world Trump could say ‘I hired these people, they do what I say,” Carafano said. “That’s not the way Washington works.”

Here’s the full 60 Minutes remarks that involved Mattis:

TRUMP: Look, yeah, I think I have a great Cabinet. There’re some people that I’m not happy with.

60 Minutes: Who are you not happy with?

TRUMP: No, I don’t want to say that. But...

60 Minutes: Come on.

TRUMP: No, I don’t want to say that. But I have some people that I’m not thrilled with. And I have other people that I’m beyond thrilled with.

60 Minutes: What about General Mattis? Is he going to leave?

TRUMP: Well, I don’t know. He hasn’t told me that. I have...

60 Minutes: Do you want him to leave?

TRUMP: ... a very good relationship with him. It could be that he is. I think he’s sort of a Democrat, if you want to know the truth. But General Mattis is a good guy. We get along very well. He may leave. I mean, at some point, everybody leaves. Everybody. People leave. That’s Washington.

60 Minutes: Is it true General Mattis said to you, the reason for NATO and the reason for all these alliances is to prevent World War III?

TRUMP: No, it’s not true.

60 Minutes: What’s not true?

TRUMP: Frankly, I like General Mattis. I think I know more about it than he does. And I know more about it from the standpoint of fairness, that I can tell you. Such a country...

[End remarks]

The speculation is likely to continue. Unlike with many of his other Cabinet members, Trump has rarely publicly rebuked his defense chief, the first time occurring earlier this year after Mattis, at a Pentagon press conference, seemed to indicate joint exercises with South Korea were back on the table.

Trump squashed the idea the next day via Twitter.

“There is no reason at this time to be spending large amounts of money on joint U.S.-South Korea war games,” Trump tweeted.

Media reports and excerpts from Bob Woodward’s recent book “Fear: Trump in the White House,” seem to indicate both leaders have also privately disparaged the other.

At the time, Mattis called the book’s revelations between he and Trump “fiction.”