'This is pretty nuts': Kayleigh McEnany struggles to defend Trump's vicious murder conspiracy theory

White House Press Secretary Kayleigh McEnany was forced to defend President Donald Trump's recent attacks on MSNBC host Joe Scarborough on Tuesday, an unenviable task she nevertheless intentionally signed up for. She desperately tried to divert the attention back to Scarborough — without engaging in the president's conspiracy theorizing — but offered no credible defense of the president's conduct.

Trump has been spreading the debunked theory that Scarborough killed a staffer in 2001 while he was in Congress, even though it was determined she died of natural causes. The staffer's widower wrote a released a letter on Tuesday pleading with Twitter to take down the president's offensive tweets promoting the thoery. He said he was "angry," "frustrated," and "grieved" by the president's promotion of the harmful allegations. Trump is perverting his late wife's memory, he said, and he fears her niece and nephews will encounter these attacks.

When asked about the letter, McEnany said she wasn't sure if the president had seen it. But she said their "hearts" are with the woman's family "at this time." It was a deeply ironic comment because the only particularly traumatizing thing about "this time" for the family is the president's attacks, which come nearly two decades after the woman's death.

McEnany refused to offer any explanation of Trump's comments and instead redirected reporters to a clip of Scarborough on Don Imus's radio show in 2003. In that show, Imus made a tasteless joke obliquely referring to the death, and Scarborough laughed at it briefly.

"Why is the president making these unfounded allegations?" asked ABC News' Jonathan Karl. "I mean, this is pretty nuts, isn't it? The president is accusing someone of possible murder. The family is pleading with the president to please stop unfounded conspiracy theories. Why is he doing it?"

"The president said this morning, this is not an original Trump thought. And it is not," she said, bringing up the Imus clip. But she made no mention of why the president is bringing up the issue 17 years later and with a much larger platform.

When pressed further on the president's conduct, she again diverted blame to Scarborough, saying his morning show unfairly criticizes the president. But again, she offered no substantive defense of Trump.

After McEnany had moved on, PBS reporter Yamiche Alcindor brought it up again: "Why won't the president give this widower peace and stop tweeting about the conspiracy theory involving his wife?"

McEnany said she had already answered the question, which she hadn't, and said the onus is on Scarborough to explain the Imus clip.

"The widower is talking specifically about the president!" Alcindor shot back. But McEnany called on Chanel Rion, with the aggressively pro-Trump outlet OAN, who changed the subject to conspiracy theories about the origins of the Russia investigation.

"Are you not going to answer that?" Alcindor called out, still trying to get a substantive response to her question, but Rion spoke over her.

At the end of the briefing, another reporter asked whether Trump was looking for any actual law enforcement steps be taken in response to his conspiracy theory. But McEnany had nothing to add, and simply told people to listen to the Imus clip again. As she hurried out of the briefing room, a reporter asked if Trump would stop promoting the theory — but she left without answering.

Watch the briefing below: