Political operative Roger Stone believes Donald Trump could find a solid running mate in either Governor John Kasich or Sen. Marco Rubio, despite huge policy differences and rhetorical bombs Trump has thrown at each rival candidate.

Stone told Politico’s Glenn Thrush that Kasich and Rubio “would be perfectly serviceable as running mates” for Trump in a general election. The comments came during an hour-long interview for Thrush’s “Off Message” podcast (beginning at 1:02:25).

THRUSH: Who would you recommend, just kind of looking at the field right now, as a running mate for him?

STONE: I do think — and he’s already said this — that he would be better off with somebody who has some experience in government who could then function as an implementer for his policies. He’s an outsider; he would be the first outsider president, really, since Reagan. You can argue that Reagan was an insider because he has two terms as governor, but I reject that. He comes to politics and government from acting and being a union president, which is an important factor. So you probably want a running mate who could facilitate your program and get it done, help get it done.

THRUSH: Gimme some names, dammit. [Laughs]

STONE: Well, if I give you any names, then I’m gonna hear from some—

THRUSH: Gimme one. Just gimme one.

STONE: Well, you could take John Kasich, you could take Marco Rubio. Either one of them would be perfectly serviceable as running mates. They both come from battleground states that are important.

THRUSH: You would have to rebrand: maybe “Medium Marco” as opposed to “Little Marco”? [Laughs]

STONE: Look, we both know that Lyndon Johnson authorized the break-in at John Kennedy’s doctor’s office here in New York to secure his medical files, and then only days later, his chief operative John Connally has a press conference to announce that John Kennedy’s far too sick — may not even live through a first term. And these guys got on the ticket together — which is why Bobby Baker, Secretary of the Senate, Lyndon Johnson’s right-hand man, says on the day that John Kennedy is inaugurated, says, “Jack Kennedy will die a violent death and he will not live out his term.”

Stone offers this historic precedent of primary rivals putting their campaign attacks behind them, but the bigger question on Kasich and Rubio is whether Trump’s base can trust the billionaire candidate to stick to his guns on populist-nationalist issues like immigration and trade policy.

Rubio, in particular, has put a face to conservatives’ worst fears. After his election to the Senate, thanks to a Tea Party-led Republican surge, he lent his name and voice to the infamous “Gang of Eight” immigration bill and left the grassroots questioning his every move — even whether he would stop Obama’s executive orders granting amnesty to illegal immigrants.

Kasich, too, has blasted Trump’s immigration proposals on deportation and a temporary pause in Muslim immigration for the sake of national security. When asked about Trump’s Muslim ban after the Brussels jihadist attacks, he outlined an alternative anti-terror strategy: “We are going to have to have intimate communication and coordination with our friends in the Muslim community. There is no question about it.”

Thrush followed up by asking Stone to speculate on a pick for White House Chief of Staff; Stone demurred and said Trump is “his own man.”

THRUSH: Chief of Staff is probably just as important as the Vice President for this guy. Who — so, Roger Stone is his ambassador to — not mainstream politics but sort of conventional politics, right? Who will be this guy’s ambassador to governance? Who is the person — who is his James Baker? Do you see someone out there, who you, Roger Stone, would like to install in the middle of this thing to ensure that this guy can really run the country?

STONE: I wouldn’t even presume to tell him who he should choose. He’ll choose somebody he—

THRUSH: Presume to tell me. [Laughs]

STONE: Well, if I do that, I’ll be telling the world. I don’t have a brilliant idea in this regard. He’s very much his own man; he’s gonna make those choices himself and he is more than capable of thinking outside the box, so I actually think he is going — he will be a great president because he is committed to large goals and he sees the big picture. And he has executive experience; he’s a guy that’s built a multi-billion dollar international business with thousands of employees, so he’s a guy who’s actually run something complex. That’s far better training to become president than, say, being a U.S. Senator, who runs nothing.

Trump will face off against Kasich and Ted Cruz Tuesday night in five state primaries – Connecticut, Delaware, Maryland, Pennsylvania, and Rhode Island – which he is expected to sweep. Should he win all five states, Cruz will join Kasich as being mathematically eliminated from a first-ballot nomination at the Republican National Convention, yet both candidates will remain in the race hoping to ensure a contested convention.