(CNN) Donald Trump loves non-disclosure agreements. In his life before politics, he regularly used NDAs to ensure discretion from his employees, should they become former employees.

That's relevant today because of the ongoing debate over whether former White House aide Omarosa Manigault Newman signed an NDA -- and whether she is in violation of it now with her tell-all book on her time in Washington. On Monday, Trump tweeted this : "Wacky Omarosa already has a fully signed Non-Disclosure Agreement!" But Omarosa told PBS NewsHour anchor Judy Woodruff earlier this week that she "never signed that draconian NDA that they presented to me when I walked into the White House."

Who's right -- legally speaking? For answers, I reached out to Heidi Kitrosser , a law professor at the University of Minnesota Law School, who specializes in "the constitutional law of federal government secrecy and on separation of powers and free speech law more broadly." Our conversation, conducted via email and lightly edited for flow, is below.

Cillizza: We know that Trump asked lots of his senior staff to sign NDAs in the 2016 campaign. Would those potentially still be binding?

Kitrosser: That gets at the core question that this situation raises, which is whether a campaign can require (and enforce) NDAs that remain binding throughout a candidate's tenure in public office. I think that the answer has to be no. If the answer is yes, then we've driven a huge hole through the First Amendment protections that would otherwise apply.

Let me break this down a bit more: Based on the one NDA that I've seen (the NDA that The Washington Post published yesterday , which Omarosa said the White House asked her to sign after she was fired, but she refused), the provisions are incredibly broad. Among other things, signers must promise never, during or after their service, to say anything disparaging about Trump, Pence, any Trump family member, etc. There's no way that a government entity or official could require such terms consistent with the First Amendment. It's a viewpoint-based prior restraint on speech of central public concern. Were an official able to get around these important protections by simply having their campaign enter the agreement (thus framing it is an agreement between private parties), such protections would have little meaning.

Cillizza: Sarah Sanders said Tuesday that "it's actually very normal, and every administration prior to the Trump administration has had NDAs, particularly specific for anyone who had a security clearance." Is that right?

Kitrosser: This is linguistic sleight of hand on Sanders' part. She slips in the words "particularly specific for anyone who had a security clearance," as though that's just one example among many type of NDAs. To the contrary, my understanding from the statements of past White House and agency employees is that NDAs are uncommon if not unprecedented APART from the national security context.

It is also important to understand that even those with security clearances have not, in the past, been prohibited from sharing anything at all about their experiences or required to sign non-disparagement agreements. To the contrary, they've been required only to avoid disclosing designated sensitive information and to submit future writings for review to ensure that they do not inadvertently leak classified information. That is a far cry from the type of broad restrictions at issue in the Trump White House.

Cillizza: What's the legal precedent -- if any -- for breaking the sort of NDAs that Trump has used in the past? Is Omarosa in any real legal peril?

Kitrosser: For the reasons that I indicate above, I don't think that Omarosa is in any real legal peril. I suspect that Trump is trying to intimidate her, and also trying to chill the speech of others who may consider speaking out about their experiences with this administration.

Cillizza: While most lawyers agree that the First Amendment will protect her in the end, that doesn't mean that Omarosa would avoid the expense of defending those rights, likely through a drawn-out and potentially costly litigation process (a la Stormy Daniels) -- which, to a client, can feel perilous indeed.