The day after the deadliest mass-shooting in American history, Donald Trump suggested to a national television audience that President Obama might be a terrorist sympathizer . Two days later, the presumptive Republican presidential nominee was even less subtle, declaring that the president “continues to prioritize our enemy over … the American people.”

In an unexpected twist, Trump yesterday said he has proof to substantiate his ridiculous claims. The Washington Post reported

Just two days after Donald Trump implied that President Obama sympathized with terrorists, provoking a backlash that included members of his own party, the presumed Republican presidential nominee declared himself “right,” based on a published report claiming administration “support” for the Islamic State. In a post to his Twitter account early Wednesday, Trump said “Media fell all over themselves criticizing what Donald Trump ‘may have insinuated’ ” about Obama. “But he’s right,” it said, linking to a story published by the conservative website Breitbart News.

The problem, of course, is that Trump is accusing the war-time president of treason based on information he clearly doesn’t understand.

As ABC News reported yesterday, Breitbart, a prominent right-wing website, relied on a memo that is “neither secret nor does it demonstrate the administration’s support for ISIS or any other policy. Indeed, it’s a recently declassified and heavily redacted intelligence field report from August 2012 about the worsening security situation in Iraq…. Breitbart falsely concludes that because the memo mentions that al Qaeda in Iraq (a precursor to ISIS) is fighting against Syrian President Bashar al-Assad, the Obama administration therefore supports ISIS.”

The Washington Post’s Glenn Kessler added , “This is what happens when people with little understanding of policy or context choose to willfully misinterpret documents. This is a relatively unimportant memo, with little information not in newspapers at the time. Rather than showing that the Obama administration is supporting terror groups, the information in the memo demonstrates why the administration was so reluctant to back rebel groups in Syria, often to the annoyance of Republican hawks.”

But before just laughing this off as the latest nonsense from a ridiculous candidate, it’s worth appreciating what stories like these tell us.

A presumptive major-party nominee for the world’s most powerful job accused the president of treason. That’s bonkers. Facing criticism, he pointed to evidence that actually proved the opposite of his intended point. That, too, is plainly outrageous.

Donald Trump is like that annoying friend on Facebook who publishes nonsense he hasn’t read and doesn’t understand, then wonders why everyone doesn’t agree with him. That annoying friend, however, isn’t trying to be leader of the free world.

I’m reminded of this recent piece from Vox’s Ezra Klein: “Among the most important tasks the president has is knowing what to believe, whom to listen to, which facts to trust, and which theories to explore. Trump’s terrible judgment in this regard is one of the many reasons he’s not qualified for the office.”

We’ve effectively reached the point at which Trump has difficulty differentiating between fact and fiction, and when pressed, his clouded mind leads him to evidence that doesn’t exist in reality. Given the fact that this man may soon be elected president, it’s not comforting.

A Republican fundraising bundler recently got his first up-close view of Trump at a California fundraiser. The GOP donor was forced to concede afterwards, “ Okay, so our guy is insane .”