In late January, Donald Trump sat down with the New York Times, which asked the president a fairly straightforward question about his re-election plans. His answer meandered a bit, before culminating in a complaint about John McCain. A week later, the Republican huddled with reporters ahead of his State of the Union address, and apropos of nothing, mocked McCain’s book sales.

Seven months after the late senator died of brain cancer, the president still can’t contain his contempt for McCain.

President Donald Trump on Saturday lashed out against an old nemesis, the late Sen. John McCain, for his crucial vote against repealing Obamacare in 2017. Trump chastised McCain for his no vote on a bare-bones repeal of President Barack Obama’s signature healthcare legislation, wrongly describing it as a “thumbs down on repeal and replace after years of campaigning to repeal and replace!”

Yesterday, the president kept the offensive going, ridiculing McCain for his grades at the U.S. Naval Academy, before retweeting a conspiracy theorist who claimed people “hated” the longtime Republican lawmaker.

The larger campaign isn’t exactly new new; Trump has been taking cheap shots at the late senator for months, as part of a creepy and unnecessary display. In this latest case, however, the president apparently feels justified in targeting McCain because of a new conspiracy theory.

According to one of many tweets Trump published over the weekend, McCain “sent the Fake Dossier to the FBI and Media hoping to have it printed BEFORE the Election. He & the Dems, working together, failed (as usual). Even the Fake News refused this garbage!”

It’s obviously classless when the president lashes out wildly at someone who can no longer defend himself, but what makes this tantrum especially offensive is the fact that Trump has no idea what he’s talking about.

At issue is Christopher Steele’s 2016 “dossier” on Trump and Russia, which is neither “fake” nor “garbage,” the president’s incessant whining notwithstanding. Trump wants the public to believe McCain tried to disseminate the document – to law enforcement and the media – before Election Day 2016.

None of this is true.

The senator was not made aware of the Steele dossier until Nov. 18, 2016 – after Trump had won the election. And there is no evidence that McCain gave the dossier to the media. Former McCain aide David Kramer, a Russia expert, testified in a deposition in the BuzzFeed libel case in Florida that he gave the dossier to the media in December 2016. McCain himself gave the dossier to the FBI, but there is no evidence that he gave it to the media.

Trump’s conspiracy theories are often ridiculous, but I don’t even see the point of this one. The president appears to simply hate McCain to such a degree that he keeps talking about – and lying about – him for no particular reason.

If Trump thinks ugly displays like these help him, he’s mistaken.