The Clintons are no strangers to scandal, both real and imagined.

Earlier this month, a new one emerged: ABC News reported that Hillary Clinton's staff tapped a top Clintonworld donor in 2011 for the International Security Advisory Board, which is tasked with giving the State Department advice about nuclear weapons and national security issues.

The donor in question, Rajiv Fernando, didn't really have extensive experience in either national security or nuclear weapons, which would seem like important qualifications for the position.

But Fernando, a Chicago securities trader, had given millions to the Clinton Foundation and fundraised extensively for Clinton’s presidential campaigns. ABC News revealed in a recent report that Fernando was added to the International Security Advisory Board at the request of Cheryl Mills, Clinton’s chief of staff at state.

The whole episode is not a good look for Clinton or her team. Internal emails obtained by ABC News show that aides wanted to "protect" Clinton from press questions about Fernando’s selection (they actually used that word). And members of the board — the actual experts with actual qualifications — have said they were perplexed by the choice.

In an email, Clinton’s staff defended the decision by arguing that the board was advisory and unpaid and that Fernando had done some foreign policy–related work. But members of the ISAB seemed largely perplexed by his presence.

"We had no idea who he was," one board member told ABC News about Fernando.

In isolation, this whole thing might not be that big a deal. Fernando isn’t a nuclear weapons expert, but he does seem like smart guy who has demonstrated a real interest in national affairs.

Perhaps most importantly, he resigned a few days after the press began asking questions about his appointment in 2011, less than a month after he was appointed — so not only is there no evidence of a quid pro quo here, there’s just little way to even say one actually came to pass.

That said, this episode could become a bigger issue on the campaign trail in part because it feeds right into the larger preexisting attacks on Clinton: that she and her husband are dangerously wedded to their big donors, and that they’d like to start repaying old favors once they begin wielding the power of the White House.

That broader fear, beyond anything a Clinton staffer said or did, is the real fuel likely to keep this particular fire burning for some time to come.

What is the International Security Advisory Board, and why would Fernando want to join it?

The International Security Advisory Board sounds like a boring, technical government agency without much glitz or glamour, prompting some to wonder why a top donor would even want to be appointed to it.

That’s a good question. But once you begin looking at what the ISAB really does, it certainly sounds like something one would enjoy bragging about at a Washington cocktail party.

Board members get a top-level security clearance. Their meetings are held at a secure location nobody else gets to know about.

In 2007, the New York Times reported that the board would be getting all the latest information about the nuclear ambitions of North Korea and Iran. Its members are some of the top experts in global stability in the world.

They get access to super-secret information and help figure out what the US State Department should do about arms control, nuclear disarmament, and other key international security questions.

This is a task force designed to help the American government avoid a nuclear holocaust that would end millions of lives. It may not exactly be as luxurious or relaxing as an ambassadorship to Barbados, but who wouldn’t want to be a part of that mission?

Why it's hard to defend the decision to appoint Fernando

A more pressing question, then, is not why Fernando wanted to be on the board but why the Clinton team chose him.

From the available evidence, it’s hard to believe that Fernando’s financial ties to Clinton didn't play at least some role in his selection, says John Wonderlich, interim executive director for the Sunlight Foundation, a money-in-politics watchdog.

Fernando has given between $1 million and $5 million to the Clinton Foundation. He maxed out his possible contributions to Clinton’s presidential run in both 2007 and 2008, according to CNN. He also raised more than $100,000 for her 2008 run through "bundling," and looks likely to max out again in 2016.

For the most part, patronage appointments have been limited in the past few decades to positions like ambassadorships with little governance function, according to Wonderlich. Giving a donor a post that might actually have a critical role in influencing government policy is a different question altogether, and the emails obtained by ABC suggest even Clinton’s team knew this didn’t pass the sniff test.

"The fact that Fernando stepped down almost immediately, and the fact that nobody tried to put up a defense when the press started asking questions, suggests they knew this didn’t add up," Wonderlich says. "It suggests something was going on that shouldn’t have been." (Fernando said in a letter to Clinton that he had to step down because of unusual "volatility" in the financial markets.)

How Clinton’s team is defending the selection of Fernando to the board

In a statement, Clinton’s campaign team suggested to Vox that the controversy was a partisan invention, referencing that the leaked emails were provided to ABC by a conservative advocacy organization.

Here’s the campaign's statement in full:

This all originates with a right-wing group that has been attacking the Clintons since the 1990s and this is just its latest attempt to​ twist the facts and​ manufacture wrongdoing by piecemeal leaks. This was an unpaid, volunteer advisory board, and one of several foreign policy-focused organizations that he was involved with. As the State Department itself has said, the ISAB charter calls for a diverse set of experiences for its members​​.

There’s some support for the idea that Fernando had some related qualifications. The ISAB tries to solve highly complex and technical issues. Fernando founded Chopper Trading, a high-velocity trading firm that works in "the most sophisticated risk management ... and code security systems in the financial industry," according to its website. (If you don’t believe that arms policy can be incredibly complex, read the latest Arms Control Wonk reporting on North Korean missile defense systems.)

The board in question deals with national security questions. Fernando may not have a ton of training in national security, but he’s now a board member of the American Security Project and a member of the Chicago Council on Global Affairs, according to ABC. So it's not as if his appointment to a national security–related post is completely out of the blue. (The Clinton campaign did not respond to follow-up questions about which "foreign policy-focused organizations" qualified him for the ISAB post.)

"The charitable case is: Of course people want their friends to be selected, because they trust and believe their friends," says Wonderlich. "And when your friends call, you talk to them, and you believe they’d be a great person for the position they say they’d be great for. It’s not hard to imagine the secretary of state or someone on her team stepping in here and doing that."

Moreover, it’s not as if the State Department was flouting any clear rules or laws about appointments. There’s no prohibition on choosing someone the secretary of state regards as simply broadly intelligent — no requirement that board members have, say, a master's degree in international relations.

"All I know is that the charter does lay out or stipulate that [they're] looking for a broad range of experiences," the current State Department spokesperson told ABC in defense of the decision to select Fernando. (He’s right.) "It’s not unimaginable that a businessman, an international businessman, might bring a certain level of expertise or knowledge or experience to such a job."

Republicans will be tempted to make hay of this — but they should be cautious

Naturally, none of these caveats featured prominently in the partisan uproar that swiftly followed the ABC News report’s release.

Longtime Clinton conspiracy theorist Newt Gingrich rushed to cry that it amounted to proof of "pure corruption." Donald Trump jumped in not long after to say that the Fernando appointment illustrates that Clinton "turned the [State Department] into her private hedge fund."

"They all looked and said where did this guy come from? He made a contribution of $250,000 and all of a sudden he's on this very important and vital board," Trump said. "This position dealt with tactical nuclear weapons and had top-secret clearance, and he knew nothing about it."

This is pretty rich, especially coming from Trump. The businessman has promised to fill his White House with "the best people" — his people. That includes his rich friends like Carl Icahn, but also Trump loyalists with no apparent expertise outside their allegiance to the billionaire.

His foreign policy team, for instance, includes a slew of extremists and woefully unqualified choices, including someone whose LinkedIn page boasted of his role in the student role-playing Model UN. It's hard to imagine, in other words, that Trump is genuinely outraged that a Clinton appointee to the ISAB didn't have extensive technical training in nuclear proliferation debates.

Now, from the narrow perspective of scoring political points, perhaps Trump has an edge here — his choices broadly reflect wide ignorance about foreign policy, but it’s difficult to single out one as evidence of corruption. The overwhelming majority of Clinton’s foreign policy team, by contrast, has been actual experts with deep knowledge of their subject matter.

Of course, that won't stop this mistake — one that was almost immediately walked back — from being amplified without end on the campaign trail. But from the actual perspective of governance, Trump’s approach is far more dangerous.

Why Democrats should still worry about this for the long term

Still, the State Department’s decision to tap Fernando isn't justified just because Trump doesn’t represent a credible alternative.

Clinton’s campaign didn’t answer several follow-up questions from Vox about its statement, including whether Clinton now believes the appointment was a mistake and which specific "foreign-policy focused organizations" qualified Fernando for the post. (A spokesperson for Fernando declined to comment.)

Unlike the emails or the Benghazi controversy, this episode reinforces one of the long-running fears about Clinton: that the separation between her donors and her decision-making isn’t absolute.

Throughout her primary campaign against Bernie Sanders, Clinton maintained that the donations she received has no influence whatsoever on her governing approach.

"Anybody who knows me, who thinks they can influence me, name anything they’ve influenced me on. Just name one thing," Clinton said at one of the debate.

Maybe the Fernando appointment is an isolated incident with no greater implications for her overall policy. We don’t even know if Clinton herself was involved in his selection, for instance.

But there’s no doubt that plenty of people who have helped the Clintons are going to want their help once they get back into the White House.

The Clinton Foundation’s list of donors runs over 330,000 names and includes the governments of Saudi Arabia and Qatar. Clinton’s website lists more than 300 "Hillblazers" — megadonors who have helped raised more than $100,000 for her 2016 campaign. She’s received millions in speaking fees from Wall Street.

Perhaps those ties really will become meaningless to Clinton once she gets sworn in. But the fact that the firewall may not have been impenetrable here suggests that it risks becoming porous once again.

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