Let’s state this very simply, so everybody will understand. The notion that Barack Obama is “Nixonian” — or that his administration’s recent troubles bear any resemblance to “Watergate” — is the biggest media lie since the phony “Whitewater scandal” crested during the Clinton presidency.

Fraudulent as it is, we have listened repeatedly to versions of this bogus comparison uttered by figures as diverse as former Fox News commentator Dick Morris and Bob Woodward of the Washington Post, alongside a phalanx of Republican politicians, including Senator Lindsey Graham and Senate Majority Leader Mitch McConnell — whose latest attack ad directly links Obama with Nixon.

Only in a country afflicted with chronic historical amnesia could they issue such accusations without shame or embarrassment. Only under those circumstances could the Republicans continue their fitful fabrication of a “Democratic Watergate” without fear of being laughed off the stage. It is a project that they will never grow tired of pursuing.

Coming from figures such as former White House political boss Karl Rove and Fox News chief Roger Ailes — both of whom worked for Nixon and defended him with vigor— the hypocrisy is stunning. They can only say words like “Watergate” or “Nixonian” because most Americans have forgotten who they really are behind the respectable masks — or never knew.

The last time we heard Obama mentioned in the same breath as Watergate was in 2009, when Rep. Darrell Issa — the same Issa who has labored for months to pump air into the Benghazi “scandal” — decided that a job offered to a potential political candidate had erupted into a Constitutional crisis. Is it necessary to note that nothing of consequence ever emerged from Issa’s investigation back then? Yet somehow, he maintains credibility with the Washington media.

So does Graham, who slandered Susan Rice over the Benghazi talking points, which he deemed “worse than Watergate” — an assertion since proved entirely wrong, irresponsible and vicious. Nevertheless Graham is treated as someone worthy of airtime and quotation, rather than a discredited blowhard.

But certain liberals in the media have fretted loudly over Obama’s “scandals,” too. Is it reasonable to compare the Benghazi incident, the vetting of abused tax exemptions by the IRS, or the Justice Department’s leak investigations with the Watergate crisis? Or is it all just trumped-up hysteria? To answer those questions, it helps to remember what Nixon and his gang actually did to America — and why they were driven out of Washington and, in many cases, sent to prison.

In these circumstances, a quick history lesson seems vital. For those who have forgotten or don’t know, Watergate is the name of an apartment complex near the Potomac River in northwest Washington, D.C., where then-President Nixon’s henchmen staged a “third-rate burglary” of the Democratic National Committee headquarters on a June night in 1972.

But Watergate came to stand for a vast agglomeration of gangster conspiracies based in the Nixon White House but spanning the nation. Watergate was a series of burglaries, warrantless domestic wiretaps, illegal spying, campaign dirty tricks, election tampering, money laundering and assorted thuggish schemes conceived by a large and lawless gang whose leaders included G. Gordon Liddy and the late E. Howard Hunt.

And Watergate grew into a cover-up of those initial felonies with still more felonies, committed by lawyers and bureaucrats who collected cash payoffs from major corporations and then handed out hush money and secret campaign slush funds.

Eventually, Watergate implicated scores of perpetrators, from the right-wing Cuban foot soldiers all the way up to the president, his closest advisors, and his crooked stooges at the highest levels of the Justice Department, the FBI and the CIA.

Again then, in what sense is the Benghazi tragedy — thoroughly investigated by an independent board, as provided by law — akin to Watergate? How is the IRS effort to vet the tax exemptions of tea party groups, which were violating their status brazenly, similar to Nixon’s criminal abuse of the agency to punish his enemies with audits? What makes the Justice Department probe of national security leaks, conducted with valid subpoenas, resemble the secret Nixon White House war against “enemies” in the press, which went so far as trumped-up FCC license challenges and even threats of violence against the Washington Post?

The answers are fairly obvious: None. Not at all. Nothing whatsoever.

And so far as we know, Attorney General Eric Holder hasn’t rung up any Fox News reporter drunkenly at midnight to warn that Roger Ailes is “going to get his tit caught in a big, fat wringer.” But if and when that ever happens, the chance to roll out the Watergate clichÇs will arrive at last — starting with “Nixonian.”