There, you would have seen the radio host Mark Levin, whose show was credited with helping to spur Mr. Trump’s accusations, laying out the case for Mr. Trump, declaring, “This is about the Obama administration’s spying.”

The proof, you would have heard him say, was already out there in the mainstream media — what with a report on the website Heat Street saying that the Federal Bureau of Investigation had secured a warrant to investigate ties between people in Mr. Trump’s campaign and Russia, and articles in The New York Times, in The Washington Post and elsewhere about intelligence linking people in Mr. Trump’s campaign to Russia, some of it from wiretaps.

“These are police state tactics!” Mr. Levin would tell you.

The next day, perhaps your Twitter or Facebook feed turned up a post from the Gateway Pundit — recently granted a White House press credential — speculating that maybe, just maybe, the F.B.I. director “Let Hillary Off the Hook Because She Knew About F.B.I. Wiretapping.”

As the week unspooled, you would have seen commentary on why Mr. Trump’s charge was so believable (Breitbart) and, shockingly, how it’s even possible that the C.I.A. hacked Clinton campaign email but made it look as if Russia had done it (Bill Mitchell, Ann Coulter, Sean Hannity).

Sure, you would have picked up static from other sources that made some of this seem ridiculous. But that stuff is for the followers of Adventure B, relying on fact-based journalism from seasoned reporters with deep contacts and established (and, yes, sometimes imperfect) protocols for fact-checking — all of which the Adventure A people view with deep suspicion that the president is only too happy to stir.

If you were among the Adventure B folk, maybe you saw James Clapper Jr., the former national security director, tell Chuck Todd on “Meet the Press” that Sunday that the F.B.I. had not secured a FISA warrant to spy on Mr. Trump’s aides.

You probably would have seen the news, first reported by The Times, that the F.B.I. director, James B. Comey, had asked the Justice Department to deny Mr. Trump’s charge (to no avail), and the viral video of George Stephanopoulos of ABC News telling a presidential aide, “That’s false,” as she tried to reprise the Adventure A argument that mainstream news reports backed Mr. Trump’s wiretap accusation.