Update: Pierson is back at it again, saying Thursday on MSNBC that Hillary Clinton suffers from a medical condition -- dysphasia -- with which Clinton has never been diagnosed. "What's new are the other reports of the observations of Hillary Clinton's behavior and mannerisms, specifically with what you just showed in those previous clips, as well as her dysphasia, the fact that she's fallen, she has had a concussion."

As I note below, it's merely the latest counterfactual claim Pierson has made this month and this campaign. While Pierson's comments have long been controversial, they have taken a particularly strange turn in recent weeks.

Donald Trump's national spokeswoman offered a pretty stunning accusation during an appearance on Fox Business Network on Monday morning. She alleged that members of the political media have "literally beat Trump supporters into submission."

"They are tired of seeing left-wing reporters literally beat Trump supporters into submission — into supporting policies that they don't agree with," Katrina Pierson said.

This is merely the latest wild accusation and strange claim made by Pierson this campaign. A charitable explanation would be that she attended the Joe Biden School of What 'Literally' Means. But Pierson does this kind of thing a lot — and she has been particularly factually challenged this month.

Just this weekend, in fact, Pierson alleged in no uncertain terms that President Obama started the war in Afghanistan, despite his having been a state senator in Illinois at the time.

"Remember: We weren’t even in Afghanistan by this time,” Pierson said. “Barack Obama went into Afghanistan, creating another problem.”

Asked to clarify whether she was accusing Obama of launching the war in Afghanistan, which started in 2001, Pierson doubled down: "That was Obama's war, yes." She later appeared to blame "audio disruptions" for her comment.

CNN wasn't buying that explanation, and media analyst Brian Stelter on Sunday pressed top Trump aide Jason Miller repeatedly on whether the campaign would continue dispatching Pierson to do TV appearances. "I don't want to scrutinize anybody too much," Stelter said, "but it seems to me there’s a pattern of misinformation. It makes me worried about where her sources of information are coming from."

Miller said Stelter was making "a ridiculous comment." But if you look at Pierson's track record, these are just the latest in a series of odd comments, and they seem to be snowballing this month. There's even a hashtag on Twitter now — #KatrinaPiersonHistory — poking fun at her grasp of historical facts.

Here are some highlights from media appearances by Trump's most Trumpian spokeswoman:

Aug. 2: Blaming Obama for the 2004 death of Capt. Humayun Khan in Iraq

Khan is the son of Khizr Khan, who spoke at the Democratic National Convention and denounced Trump's proposal to ban Muslim immigration. Humayun Khan was killed in Iraq in 2004.

But when Trump was feuding with the Khans a couple of weeks ago, Pierson went on CNN and accused Obama of being at least indirectly responsible for the younger Khan's death — despite, again, Obama not having been president or even a U.S. senator when it happened.

"It was under Barack Obama and Hillary Clinton that changed the rules of engagement that probably cost his life," she said.

Pierson later apologized for getting the timeline wrong.

Aug. 3: Incorrect military death numbers

But even explaining and apologizing for her misstatement the day before, Pierson again got it wrong.

"That's why I used 'probably,'" Pierson said of her allegation that Obama and Clinton were responsible, "because I was just going through the timeline. Because since then, we have had tens of thousands of soldiers that have been lost. One million wounded."

These numbers are grossly exaggerated. According to the Defense Department, 5,313 troops have been killed in both Iraq and Afghanistan.

Trump campaign co-chairman Sam Clovis appeared on CNN on Aug. 4 and assured that Pierson spewing incorrect facts "won't happen again." But it did.

June 27: Trump's proposed Muslim ban didn't ban Muslims

"I know the news media was reporting that the initial ban was against all Muslims, and that simply was not the case,” Pierson said on CNN about Trump's oscillating proposal to ban Muslims from entering the United States over security concerns.

But the campaign's news release from Dec. 7, 2015, which still appears on Trump's website, is quite clear.

"Donald J. Trump is calling for a total and complete shutdown of Muslims entering the United States until our country's representatives can figure out what is going on," it said at the time.

Feb. 22: Questioning Rubio's eligibility

During a time in which some, including Trump, were questioning whether Canadian-born Ted Cruz was eligible to serve as president, Pierson went a step further and questioned whether American-born Marco Rubio was eligible.

"The question here: Is he a naturalized citizen?" she said. "Now we know that his parents were not citizens at the time — that makes a huge difference with regards to eligibility.”

CNN host Jake Tapper quickly clarified that Pierson was flat wrong. "It actually doesn't," he said. "If you’re born in the United States, you're a natural-born citizen. That’s pretty much just the law."

Pierson responded, "Well, that's the anchor-baby law, yes," using a derogatory term for birthright citizenship.

That line didn't come out of nowhere. Just a few days earlier, Trump had re-tweeted a supporter who said that neither Cruz nor Rubio were eligible, natural-born citizens.

And a day or so before Pierson's interview, Trump offered much the same response to ABC's George Stephanopoulos:

STEPHANOPOULOS: You're really not sure that Marco Rubio is eligible to run for president? You're really not sure?
TRUMP: I don't know. I've never looked at it, George. Honestly, I've never looked at it. Somebody said he's not, and I retweeted it.

In other words, Pierson had just echoed her boss's comments. Like many of her statements, her opinion on Rubio's eligibility may have been factually challenged. But for a campaign led by Donald Trump, it wasn't necessarily off-message.

What Donald Trump is doing on the campaign trail

MANCHESTER, NH - NOVEMBER 7: Republican presidential candidate Donald Trump speaks during a campaign event at SNHU Arena in Manchester, NH on Monday November 07, 2016. (Jabin Botsford/The Washington Post)