Not for the first time, Donald Trump published an odd falsehood to Twitter yesterday about his predecessor and Russia’s attack on U.S. elections in 2016. “Why didn’t President Obama do something about Russia in September (before November Election) when told by the FBI?” the Republican wrote. “He did NOTHING, and had no intention of doing anything!”

We know this is wrong. In fact, it’s been debunked several times. But Trump isn’t just trying to blame Obama for the Russian intelligence operation that helped put Trump in power, his re-election campaign is trying to use a strange conspiracy theory to encourage the president’s followers to make a contribution.

President Donald Trump’s reelection campaign said in a new ad that President Barack Obama failed to counter Russian election interference and “just watched it happen” – but the video misleadingly used a clip of Obama’s top cyber adviser to make its point.

The campaign video was sent to Trump’s supporters yesterday in an email that began, “Obama knew.”

The message added, “President Obama knew Russia was interfering in the 2016 election, but his administration just watched it happen. In fact, Obama’s cyber team was told to ‘stand down’ from countering Russian meddling in order to protect the disastrous Iran deal.”

Again, as Politico’s report makes clear, the substance of the claims is plainly wrong, and it’s absurd that the Trump campaign would peddle such demonstrably false claims to its own supporters. Indeed, it follows a related recent pitch from the president’s operation, which claimed that Obama may have even “worked with Russia” on the scheme.”

But that’s really just the start of the problem.

Consider exactly what Team Trump wants donors to believe. Barack Obama was aware of Russia’s scheme to help Trump, but according to the conspiracy theory, Obama deliberately did nothing, allowing Moscow to help to put Trump in power, in order to protect an Iran nuclear agreement that Trump opposed.

Why in the world would anyone seriously believe this? Obama wanted to protect a nuclear agreement, so he ignored an attack intended to elevate an opponent who was determined to reject the nuclear agreement?

Just how foolish does the Trump campaign consider its own supporters?

What’s more, every time the Republican operation focuses anew on this, we’re reminded that Obama tried to address the attack at the time, but he faced resistance from Mitch McConnell.

Perhaps this is a good time for a refresher. As regular readers know, the Obama White House, swayed by the evidence compiled by U.S. intelligence agencies, wanted bipartisan support to push back against Russian intrusion, and in mid-September 2016, the then-president dispatched counterterrorism adviser Lisa Monaco, then-FBI Director James Comey, and then-Homeland Security Secretary Jeh Johnson to brief top members of Congress.

Obama didn’t want to be seen as using intelligence for partisan or electoral ends, so he sought a “show of solidarity and bipartisan unity” against foreign manipulation of our democracy.

That didn’t happen – because McConnel refused.

As the Washington Post previously reported, when national security officials told congressional leaders about Russia’s interference, it was McConnell who not only didn’t want to alert the public, he also questioned the validity of the intelligence.

Someone chose to do “nothing,” but it wasn’t the Democratic president.

Postscript: I’d be remiss if I failed to note that in the Trump campaign’s message, it’s simply stated as fact that Russia interfered in the 2016 election. Isn’t that a basic detail that Donald Trump himself has spent much of the last three years denying?