Everyone is talking about Donald Trump’s call for the Russian government to release emails it may have stolen from Hillary Clinton’s private email server. But that wasn’t the most chilling thing Trump said in his rambling answer to a question about who hacked the email server of the Democratic National Committee.

"Honestly, I wish I had that power," Trump responded. "I’d love to have that power."

The thing is, if Trump gets elected president, he probably will have the power to hack into the private communications of his political opponents. And that’s terrifying.

The NSA gives the president immense spying powers

Thanks to whistleblower Ed Snowden, we know that the National Security Agency has one of the most sophisticated offensive hacking programs in the world. The NSA has a team of researchers who look for security vulnerabilities in popular technology products, and it also sometimes buys information about security vulnerabilities from outside hackers. That means the NSA is often able to break into computer systems that would repel less sophisticated hackers.

The NSA also has broader surveillance capabilities. The Snowden revelations showed that the agency was engaging in dragnet surveillance of Americans’ call records and had streamlined access to users' data on online services like Yahoo Mail and Google Docs.

The NSA, of course, is supposed to focus these resources on hostile foreign governments and terrorist groups. But in principle, a future president could turn those capabilities inward, using them to spy on domestic political opponents, journalists, and activists.

As we learned during the early years of the George W. Bush administration, there are few practical limits on the president’s surveillance powers. When lawyers advised Bush that a proposed dragnet surveillance program exceeded the NSA’s authority under the law, the president ordered the NSA to do it anyway.

Hopefully if President Trump ever ordered the NSA to hack into the computer systems of domestic opponents or critics, NSA leaders would refuse. But the president has the power not only to choose the NSA director but also to prosecute whistleblowers for leaking classified information. So we shouldn’t be too confident that internal resistance at the NSA would stop him.

Trump has threatened to retaliate against critics as president

Trump has repeatedly signaled a willingness to use the powers of the presidency to retaliate against critics and political opponents. For example, he has not only threatened to change libel laws to make it easier to sue the Washington Post but also threatened the paper’s owner, Amazon CEO Jeff Bezos.

"If I become president, oh, do they have problems. They're going to have such problems," Trump said. He suggested that he could retaliate against Bezos for the Washington Post's work by opening an antitrust case against Bezos's company, Amazon.

Trump has repeatedly praised the "strength" of authoritarian leaders around the world, including Vladimir Putin in Russia and the government of China.

These kinds of comments are so far outside the norms of conventional American politics that they’re easy to laugh off. We’ve enjoyed the benefits of liberal democracy and the rule of law for so long that it’s hard to imagine a president using the immense powers of his office to spy on or retaliate against his critics.

But a candidate’s statements on the campaign trail are usually a pretty good guide to how he'll govern in the White House. Donald Trump keeps hinting that he’d emulate dictators like Vladimir Putin and use the powers of his office for political advantage. We should take him seriously.

The possibility of President Trump shows the dangers of broad NSA power

President Obama has made some efforts to bring greater oversight to the NSA’s surveillance activities. He claims to have shut down one of the NSA’s most controversial programs last year, and he signed a modest package of reforms called the USA Freedom Act.

But the breadth of the NSA’s surveillance capabilities, combined with weak oversight and the secrecy surrounding its activities, makes the agency inherently difficult to rein in. The Obama administration has aggressively prosecuted whistleblowers liked Thomas Drake who talked to the press about illegal government surveillance activities. So if the NSA begins to break the law again in the future, people who know about it might be too afraid to alert the public.

So there’s still more work to be done if we want to ensure that future presidents do not turn the NSA’s immense powers to nefarious ends.

The political science that predicted Trump's rise