US Republican presidential candidate Marco Rubio at the Freedom Summit in Greenville, South Carolina. Thomson Reuters Sen. Marco Rubio (R-Florida) has chimed in on Apple's war with the FBI — and he is being praised for his "nuanced" answer.

The FBI this week obtained a court order to force Apple to help it break into an iPhone belonging to one of the two San Bernardino shooters. Apple is challenging the order, arguing that being forced to build a "backdoor" will make its users less safe.

Apple CEO Tim Cook wrote in an open letter that company feared "that this demand would undermine the very freedoms and liberty our government is meant to protect."

Rubio thinks Apple should "voluntarily comply" — but he has acknowledged some of the key fears of privacy activists.

"If we passed a law that required Apple and these companies to create a backdoor," the Republican presidential hopeful said on CNN, "one, criminals could figure that out and use it against you. And number two, there's already encrypted software that already exists, not only now but in the future created in other countries. We would not be able to stop that, so there would still be encryption capabilities — they just wouldn't be American encryption capabilities."

These are two common arguments against weakening encryption and privacy protections. There's a common saying in privacy circles — "you can't create a backdoor that's only used by the good guys." Any attempt to weaken security will always be open to abuse by malicious actors, the logic goes.

And on the second point, Rubio is dead on. A recent Harvard study found that encryption products are being developed in 35 jurisdictions outside the US.

It concluded: "Encryption products come from all over the world. Any national law mandating encryption backdoors will overwhelmingly affect the innocent users of those products. Smart criminals and terrorists will easily be able to switch to more secure alternatives."

Rubio has been one of the most aggressive Republican presidential candidates on national-security issues, so his tone on the Apple issue is somewhat surprising. Rubio strongly criticized Sen. Ted Cruz (R-Texas), one of his main presidential rivals, for voting to curtail the NSA's metadata-gathering program, for example.

Rubio added of the encryption issue: "We're going to have to figure out a way forward working with Silicon Valley and the tech industry on this. There has to be a way to deal with with this issue that continues to protect the privacy of Americans but creates some process by which law-enforcement intelligence agencies could access encrypted information. I don't have a magic solution for it today — it's a complicated new issue."

As the New York Post reports, Rubio thinks Apple should voluntarily comply — "ultimately, I think being a good corporate citizen is important" — a position many in the tech industry vehemently oppose. There are fears that the case could set a dangerous precedent, that companies can be legally compelled to hack into their users.

But his recognition of the issues at stake is earning him praise.

Ben Thompson, a tech commentator, shared a video clip of Rubio's answer on Twitter. He said it was "a far better answer to the Apple/FBI question than I expected from any politician."

Mike Isaac, a tech reporter for The New York Times, said Rubio had a "fairly nuanced appreciation" of the debate.

Others on Twitter were similarly positive.

Donald Trump, the Republican presidential front-runner, is far more forthright on the issue. He blasted Apple over the issue, asking ,"Who do the think they are?"

"I agree 100% with the courts," Trump said. "In that case, we should open it up. I think security overall — we have to open it up. And we have to use our heads. We have to use common sense. Somebody the other day called me a common-sense conservative. We have to use common sense. Our country has so many problems."

On Tuesday night, Google CEO Sundar Pichai came out in support of Apple. "Forcing companies to enable hacking could compromise users' privacy," he wrote on Twitter. "We know that law enforcement and intelligence agencies face significant challenges in protecting the public against crime and terrorism. We build secure products to keep your information safe and we give law enforcement access to data based on valid legal orders. But that's wholly different than requiring companies to enable hacking of customer devices & data. Could be a troubling precedent."

One commenter had a pretty spot on joke, calling out Rubio's recent "robot-like" debate performance.