Down at the courthouse, the kind of story Donald J. Trump is peddling is laughingly called the “some-other-dude-done-it” defense.

Among the president’s 23 (!) separate denials that his presidential campaign “colluded” with Russia during a half-hour New York Times interview was this preposterous line: “I actually think it’s turning to the Democrats because there was collusion on behalf of the Democrats. There was collusion with the Russians and the Democrats. A lot of collusion … starting with the dossier.”

OPINION

The other dude, in Trump’s addled mind, being “Crooked Hillary.” She’s the one that conspired with Vladimir Putin!

You see, deep thinkers on the right have been arguing that it was a partially unverified report written by former British intelligence operative Christopher Steele that first convinced the FBI to open a counterintelligence investigation of Trump’s dalliance with the Kremlin.

And since the Democrats (taking over from anti-Trump Republicans) had partly paid for the so-called “dodgy dossier,” the entire Russia probe amounted to nothing more than a “deep state” dirty trick. Because, as everybody knows, investigating a crime is exactly the same thing as committing one — an absurdly circular argument that would render law enforcement impossible.

Which in the case of Trump and the Russians, is exactly what’s intended. To Trumpists, “deep state” refers to anybody and everybody in the U.S. government whose first loyalty is to the Constitution rather than to Donald J. Trump.

Just ask around at your friendly, neighborhood penitentiary. Maybe half the inmates will assure you that an unholy conspiracy among cops, prosecutors and lying witnesses is what put them there.

Once in a blue moon, it’s even true.

But I digress. Some fervid Trumpists even began to talk about a “purge” of the FBI — language no American should use.

So somebody decided to set the record straight. The New York Times delivered itself of a New Year’s Eve blockbuster. See, it turns out that it wasn’t the Steele dossier that caused the FBI to open an investigation of the Trump campaign in the summer of 2016 at all.

“Instead,” the Times revealed, “it was firsthand information from one of America’s closest intelligence allies.” Specifically, Australia.

“During a night of heavy drinking at an upscale London bar in May 2016, George Papadopoulos, a young foreign policy adviser to the Trump campaign, made a startling revelation to Australia’s top diplomat in Britain: Russia had political dirt on Hillary Clinton” in the form of stolen emails.

“I can speak from experience,” my pal Charles Pierce has written. “Drinking with Aussies is not for rookies.”

Certainly not in Papadopoulos’ case. At first, the Australians didn’t know what to believe. But two months later, as stolen DNC emails embarrassing to the Clinton campaign began to appear on Wikileaks, the Australians took what they knew to the FBI: At some level, the Trump campaign was in cahoots with the Kremlin. Only afterward were FBI agents dispatched to interview Christopher Steele — a respected intelligence professional.

Along with the Aussies and the Brits, Germany, the Netherlands, Poland, France and Estonia also provided intelligence to the Top Secret investigation.

The Times story also establishes that far from being the insignificant “coffee boy” depicted by Trump loyalists after he pleaded guilty to lying to the FBI, Papadopoulos exercised real influence at key intervals. Guided by one Olga Polonskaya, a young woman from St. Petersburg posing as Vladimir Putin’s niece, he helped to craft Trump’s first major foreign policy speech on April 27, 2016 — in which the candidate spoke warmly about Putin, with Russian Ambassador Sergey Kislyak seated in a position of honor.

While the Times could not confirm that Papadopoulos told the Trump campaign what he told the Aussies about Russian espionage, what would you say are the odds that he kept the secret to himself? Moscow was his meal ticket. With Papadopoulos as a cooperating witness, we can be confident that by this time Robert Mueller’s investigators know for sure.

What the Russians wanted was a relaxation of economic sanctions imposed by the NATO countries as a consequence of their seizing Crimea and invading eastern Ukraine. Seen from that perspective, everything that happened subsequently — public and private — looks like a protracted negotiation between Trump and the Kremlin.

Thus, when Russian operatives promised “dirt” on Hillary Clinton before the famous June 16 meeting in Trump Tower, Donald Jr. almost certainly thought he knew exactly what they had. And when his father the presidential candidate said in a July 2016 press conference, “Russia, if you’re listening,” the indefatigable Seth Abramson argues, “he a) knew they were listening, b) knew they’d stolen the emails he was urging them to release, and c)… had already promised … to reward them for being good to him.”

Meanwhile, anybody down at the courthouse could tell Trump that if he really expects to be believed, 23 denials are about 21 too many.

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