Now, 55 years later, we have an abnormal presidential candidate who actually won, and an F.B.I. that definitely ran a secret investigation into his highly-unusual campaign. We can wrangle over whether to use the term “spying” to describe sending informants to meet with a Trump campaign aide, George Papadopoulos, under false pretenses and subjecting another aide, Carter Page, to wiretapping. But having the law-enforcement arm of the executive branch surveil a presidential nominee from the opposing party is still the kind of case where, in a non-Trump context, anyone suspicious of our security state would smell a rat.

Of course we are not in a non-Trump context, and as someone who shared the establishment’s fears about his candidacy, I’ve long assumed the combination of the Russian hacking and the shadiness of Trump’s campaign associates created a reasonable predicate for investigation — especially since, unlike with L.B.J., there is no evidence that it was used for partisan advantage during the campaign itself.

But now that the Mueller investigation has concluded that whatever the F.B.I. thought they saw happening was probably not, in fact, the kind of complex conspiracy suggested by Christopher Steele’s infamous dossier and other maximally alarmist theories, it’s reasonable to ask some more questions about the don’t-call-it-spying carried out against the Trump campaign.

Here are two of mine. First: Were any other entrapping approaches made to Trump campaign officials, and by whom? Throughout this controversy, running in parallel to the Steele/MSNBC theory of Trump-Putin conspiracy, there has been another conspiratorial reading of events, which alleges a pattern of outreach to the Trump campaign by intelligence-community and Clintonworld affiliates masquerading as Russian envoys. “Taken together,” wrote Lee Smith last summer, “these efforts could be interpreted not as an investigation but a sting operation intended to dirty a presidential campaign.”

I’m generally as skeptical of this counterconspiracy theory as of the maximalist collusion case. But it would be helpful to know more about some of the ambiguous characters involved. For instance, was Stefan Halper, the Cambridge academic used by the F.B.I. as a confidential informant, doing any outreach to Trumpworld before the F.B.I. investigation formally began, as the counter-conspiracists suggest? And what actually became of Joseph Mifsud, the mysterious Maltese professor whose meetings with Papadopoulos, in which Mifsud claimed to have high-level contacts in Russia, set in motion events leading to the F.B.I. opening its case? The counter-conspiracists suspect Mifsud of being connected to Western intelligence rather than the Kremlin, but nobody can ask him because he has simply disappeared.