Now the final decision on whether to block the memo from becoming public lies with the White House. The F.B.I., which has reviewed it, issued a rare public warning against its release, citing “grave concerns about material omissions of fact that fundamentally impact the memo’s accuracy.” Nevertheless, reports on Thursday indicated that Trump had decided to allow the memo’s disclosure.

All this drama might make you think that the memo’s claims are scandalous. But part of what’s so weird and disorientating about this whole episode is that, in a normal political environment, no Republican would want to draw attention to the F.B.I.’s reasons for surveilling Page. As The Wall Street Journal reported on Thursday, Page has been on the radar of counterintelligence agents since at least 2013. A 2015 criminal complaint against two suspected Russian spies, Victor Podobnyy and Igor Sporyshev, cited an intercepted conversation about their efforts to recruit a man “working as a consultant in New York City.” Page has acknowledged that he was the man they were referring to, and admitted to passing documents to the Russians.

According to CNN, Page was the subject of a secret intelligence surveillance warrant in 2014, well before the beginning of Trump’s presidential campaign. Despite this, Trump identified Page as one of his key foreign policy advisers in March 2016. Later that year, the F.B.I. received a new secret warrant to monitor Page’s communications after he traveled to Russia, where he met with multiple Russian government officials.

Thanks to reporting on the memo, we know that Rosenstein, a Trump appointee, saw fit to apply for this warrant’s renewal. This suggests that one of the most senior figures in Trump’s own Justice Department thought it was credible that Trump had someone on his campaign who had been compromised by Russia. Only in a crazy alternate universe does that exculpate the president.

Unless, that is, you believe that it is illegitimate for intelligence agencies to be watching Trump associates. And to believe that, you have to start with the premise that Trump is innocent and the agencies are corrupt. The controversy around the Nunes memo works to insinuate these assumptions into the public debate. It may also give Trump the very thinnest of pretexts to fire Rosenstein, which would be a first step toward attempting to shut down the Russia investigation.

If and when it’s released, the Nunes memo will probably only vindicate Trump among people who already share right-wing assumptions. But it will put the F.B.I. in a difficult position, since to defend itself against accusations that it relied solely on Steele’s findings to get a warrant on Page, it would have to release additional classified evidence. (CBS News reported on Thursday that, if the memo is released, the F.B.I. is prepared to issue a rebuttal.)