Here’s a startling and depressing statistic: 74 percent of Republican voters think it’s at least “somewhat likely” that Donald Trump’s offices were wiretapped during the campaign — a conspiracy theory that has been conclusively shot down by the leaders of Trump’s own party and by the heads of both the FBI and the National Security Agency.

That suggests the Trump administration’s strategy of refusing to back away from the unfounded assertion may be paying off, at least with his GOP base, and at least for the moment. It also suggests House Intelligence Committee Chair Devin Nunes’s efforts to deflect attention away from Trump by making unfounded allegations of his own could be working politically, despite what they’re doing to the lawmaker’s own credibility.

The findings come in a new CBS News poll that found just 13 percent of Republicans accept the US intelligence community’s findings that Russia interfered in the 2016 election to help Donald Trump, compared with 40 percent of Democrats. The divide is even more striking when it comes to Trump’s allegation that President Obama ordered the FBI to tap his phones during the campaign:

Those numbers should be troubling, regardless of one’s party affiliation. Trump has had a rocky few months in office, but it’s understandable how many conservatives would still find much to like in his stated commitment to pursuing some form of tax reform and in his nomination of Neil Gorsuch to the Supreme Court. Neither will be easy, but wins on both are well within the realm of the possible.

Russia is a different story. An array of Trump aides are known to have lied about their contacts with Moscow, and the entire US intelligence community — literally every part of it — believes Russia hacked the Democratic National Committee and timed the release of specific troves of emails to hurt Hillary Clinton and help Trump. The GOP used to be a party that boasted about its support of law enforcement and its staunch opposition to Russia. Trump is somehow managing to change all that.

Trump isn’t the only one trying to hide his campaign’s ties to Russia

In fairness, Trump is getting valuable help from the person charged with leading the congressional investigation into Russia’s election meddling: Nunes, the House Intelligence Committee chair.

As I wrote this morning, the seven-term GOP lawmaker — and member of the Trump transition team — is at the center of a widening scandal over whether he has been collaborating with the White House to shield Trump from the continuing political fallout over the president’s wiretapping allegations.

The Nunes controversy began last Wednesday, when he used a pair of press conferences to announce that he’d seen intelligence reports showing that US spies “incidentally collected information about US citizens involved in the Trump transition,” including the president himself as well as others who now work in the administration.

Nunes later said he met with an unnamed source at the White House complex who gave him classified information purportedly validating some of Trump’s claims. (To be clear: It doesn’t.)

Nunes has steadily refused to detail the information or identify his source. The fact that he met that unnamed person at the White House complex raises the real possibility that the source was a member of the administration. In other words, Nunes may have used information he received from the Trump White House itself to publicly try to deflect blame from Trump.

None of that has changed the fact that the congressman’s deliberately vague and murky explanations of exactly what he’s seen — and where he’s gotten it — may have helped Trump persuade at least part of the American public that the president’s wiretapping allegations have some validity (again, they don’t).

In the immediate aftermath of Nunes’s disclosures, Trump said the comments left him feeling “somewhat” vindicated, while the Republican Congressional Committee sent a list-building email with the subject line “Confirmed: Obama spied on Trump.”

Nunes said no such thing, and his comments did no such thing. But that may not matter for many GOP voters. In the current environment, real news gets dismissed as fake news, fake news gets accepted as fact, and we wind up with an unfounded conspiracy theory being accepted by three-quarters of Republican voters. All that and we’re not even to April yet.