On Tuesday, White House press secretary Sarah Huckabee Sanders was asked about whether President Trump was involved in the crafting and pushing of the Seth Rich conspiracy theory, as a new lawsuit alleges. She denied Trump’s involvement in any way: “The president had no knowledge of the story and it's completely untrue that he or the White House had any involvement.”

That's good. Former White House press secretary Sean Spicer said that he met with the lawyer who funded the Rich investigation, Ed Butowski, in April. He told NPR, “It had nothing to do with advancing the president’s domestic agenda – and there was no agenda. They were just informing me of the story.” Huckabee Sanders’ statement isn’t in conflict with Spicer’s.

But then Huckabee Sanders was then asked whether Trump believes the conspiracy theory that Rich, a Democratic National Committee staffer, was actually working for Wikileaks and handing them material from the DNC, and was then murdered in connection with his activities. Huckabee Sanders’ answer: she was “not sure.”

Here we get to a nasty problem for White House press spokespeople: while it would be beneficial to the president to disown evidence-free conspiracy theories, Trump himself could go on Twitter and destroy any denial at any time. He has repeatedly undercut members of his own administration after they go out on a limb for him – in fact, in this press conference, Huckabee Sanders was forced to acknowledge that Trump was involved in drafting Donald Trump Jr.’s public statement on his 2016 meeting with Russian-involved lawyers, leaving his own lawyer, Jay Sekulow, out to dry. Sekulow isn’t the first, and he won’t be the last.

That means that press secretaries aren’t free to assume even the most rational responses to the most ridiculous questions. They have to fear that Trump will immediately blow them up. Which means that the media can have a field day by asking White House press secretaries about every ridiculous theory under the sun, and then using non-denials to smash Trump. Here’s the line of questioning:

Media: “Does the President believe the moon is made of cheese?”

Huckabee Sanders: “I am not sure. We haven’t spoken about that.”

Headline: “PRESIDENT MAY BELIEVE MOON MADE OF CHEESE.”

That’s Trump’s fault, of course. Were he predictable in any way, the press secretary would have an easy job: of course the president doesn’t believe the moon is made of cheese!

But Trump isn’t predictable. He’s unstable, and he does tend to believe half-crazy conspiracy theories (see Obama’s birth certificate, anti-vaccination lunacy, Rafael Cruz’s involvement with the JFK assassination). It’s a tough job being press secretary under the best of circumstances. With a client like President Trump, that job becomes nearly impossible.