The cliche about the Russia investigation is that there’s a lot of smoke, and with the firing of FBI Director James Comey, President Donald Trump rolled a military-grade smoke grenade into the room.

There were many legitimate reasons to fire Comey, who repeatedly went outside Department of Justice guidelines to comment on the investigation of Hillary Clinton during last year’s presidential campaign. Annoyance with his handling of the Russia investigation isn’t one of them.

The firing has stoked charges of a cover-up and again raised the questions, Why, if Trump has nothing to hide, does he act so guilty? Why, if there’s no fire, is there always so much smoke?

But so far, the scandal is nothing but smoke: We get hints of what might be, pending further revelations, serious misconduct, always augmented by Trump’s defensive bluster. It’s all highly suspect, yet it’s hard to see what exactly will constitute the grave underlying offense.

The most plausible of these suspicions, that the Trump campaign colluded with the Russians, has never made much sense on the face of it. The Russians hacked Democratic National Committee and Clinton campaign emails and walked across the street to hand them over to WikiLeaks for dissemination. Why would any coordination with the Trump campaign be necessary?

Then there’s the motley crew of Page, Manafort &Flynn, the former advisers evidently at the center of the Russia matter. According to The New York Times, Carter Page occasioned the FBI investigation into Trump’s campaign when he traveled to Moscow for a presentation last July. Page, listed as a Trump foreign-policy adviser when the campaign was desperate for any names, is the very definition of a marginal player.

As for former national-security adviser Michael Flynn, a haze of sketchiness surrounds him. But his offenses have to do with the alleged failure to adequately disclose lobbying work and get Pentagon approval for a paid speech for RT in Moscow (none of which involves Trump), and his deception about the content of phone calls with the Russian ambassador during the transition (for which he was fired).

Then there’s Paul Manafort. He’s a stereotypical slippery Washington operator. It’s very easy to believe that his business dealings deserve to be under investigation, but Trump fired him last August.

In short, it’s entirely possible that none of this really has anything to do with Trump directly. Yet he’s been a human smoke-making machine.

He is simply incapable of a little deftness. During the campaign, he could have easily said, “It’s clear the Russians are behind this hacking and I’m appalled by it, but boy, is Hillary Clinton corrupt.” After the campaign, he could have said, “I support any and all investigations to get to the bottom of the Russian hacking.” Anytime over the past few months, he could have said, “If there was any collusion with Russia by people in my campaign, I knew nothing about it, and I want them exposed expeditiously and punished harshly.”

Maybe Trump doesn’t say these things because he has a cognizance of guilt and fear of exposure. But there’s a ready, innocent explanation: He never makes a concession against interest. He knew admitting the Russians were involved in the hacking during the election would make his attacks on Clinton a little more complicated. He feared that any additional focus on Russia after the election would legitimize Democratic claims that the election was stolen, and considers every insinuation about Russia an attack on his standing and honor.

So he fights back hammer and tongs, and his critics sense something rotten lurking underneath the combativeness.

Even if there’s nothing at the bottom of the Russia matter, Trump and his team are still in jeopardy. Washington scandals have a way of becoming about the handling of the scandal, and the firing of Comey may signal the beginning of that phase. Certainly that’s the hope of the Democrats. Where there’s smoke, in other words, they want to make fire.

Rich Lowry can be reached via e-mail: comments.lowry@nationalreview.com.