The National Whistleblower Center’s Executive Director on Trump’s Reactions to the Ukraine Call Leak

It’s not an understatement to say that John Kostyack is closely watching who may be coming forward next with information about that controversial call between U.S. President Donald Trump and Ukranian President Volodymyr Zelensky.

Kostyack is the executive director of the National Whistleblower Center, a Washington, D.C.-based nonprofit advocacy group that helps to protect and encourage whistleblowers in the corporate and political fields to come forward, despite the impact it may have on them professionally and personally.

The Whistleblower Protection Act of 1989 protects federal whistleblowers who work for the government from actions or threats of retaliation. Trump has been accused of violating this act by several House Democrats, including presidential candidate Sen. Kamala Harris (D-Calif.), who asked Twitter to suspend Trump’s account.

Now, with not one, but two whistleblowers at the center of Trump’s impeachment inquiry, the president has continuously disputed their accounts, including in a series of tweets on Wednesday.

“No Pressure at all said Ukraine! Very congenial, a perfect call,” Trump said in one of the tweets. “The Whistleblower and others spoke BEFORE seeing the Transcript. Now they must apologize to me and stop this ridiculous impeachment!”

Is Trump violating the Whistleblower Act with his comments—or just walking a fine line? Kostyack weighs in.

Q: Why is there so much scrutiny about if the whistleblower is protected or not?

A: The House (of Representatives) needs to hear from the whistleblower, and their identity deserves the full protection by the laws afforded to them. The whistleblower is fully cooperating. The whistleblower has complied with the law, and that’s what the intelligence community has said.

The belief that some laws may have been violated or if the president may have abused his authority are reasons the whistleblower, both whistleblowers are protected. They are exercising their rights under the umbrella of protection. Both whistleblowers have skilled attorneys with sympathetic ears, and we’re cautiously optimistic their identities will be kept under wraps. We hope that continues.

Q: Why is the president so determined to reveal the whistleblowers’ identities?

A: That’s opposite a longstanding, centuries-old whistleblower law from the founding of this country. Whistleblowers are needed. An environment has to be created where they are not punished. Unfortunately, there’s a long history where whistleblowers have been punished, threatened, their families have been threatened. We always advocate for real strong consequences if their protections are violated.

Fortunately, we have a bipartisan consensus, including from (Iowa GOP) Sen. Chuck Grassley, one of the architects of the whistleblower law, that we want whistleblowers to step forward, be heard and protected.

The heart of a whistleblower is they can’t stand to sit silent and let the abuse of the law go by, to call out any laws that have been violated. And, after all they have been through, after all the trauma and backlash, they almost all say uniformly they will do again because they have a strong sense of right and wrong.

Whistleblowers are also entitled to their anonymity. They should not be subjected to any direct or implied threats, and there should not be calls to have their identities exposed. There’s this growing mainstream view, however, to expose them now and send a message to all whistleblowers to intimidate them.

Q: Why is the president lashing out at the whistleblower(s) so blatantly?

A: He’s feeling under attack. It’s like shooting the messenger. The president and his allies are trying to shift the attention on the whistleblower’s credibility and personally attacking this individual.

It’s one thing if they were testifying at trial, but they are not. We are not in a trial situation. They are giving investigative leads to both Republicans and Democrats in Congress to follow up with. That’s what the whistleblower laws are set up for. If there were to be a trial, it would happen in the Senate and the House would decide which witnesses would testify. At that point, the president, who would be the defendant, would have the opportunity to confront his accusers. We’re not at that stage yet.

We are not to supposed to have the president and other senior officials threatening (the whistleblowers). It’s way too early to think they will be star witnesses. They have fulfilled their patriotic duties by providing evidence to investigators. This is not a case where the whistleblowers’ credibility will determine the president’s fate. His actions will.

More must-read stories from Fortune:

A running list of questions on the impeachment inquiry, answered
—White House claims Trump impeachment inquiry violates procedure
5 lessons history has taught us about impeachment
What is CrowdStrike, the company Trump mentioned during his Ukraine call?
—How the circumstances around Donald Trump’s impeachment inquiry differ from Bill Clinton’s
—How whistleblowers have taken down titans of American business
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