I  was representing the Clinton campaign . . . except when I wasn’t.

That is the defense that Democratic lawyer Michael Sussmann floated to the jury as his criminal trial kicked off in Washington with opening statements and the first government witnesses. Sussmann is charged with one count of lying to the FBI in the first trial generated by special counsel John Durham’s Russiagate investigation.

As laid out in the opening statement of Durham prosecutor Deborah Brittain Shaw, Sussmann is alleged to have lied to the FBI — specifically, to its then-general counsel, James Baker — in order to conceal the fact that he was representing the Clinton campaign, as well as Rodney Joffe, an Internet-services expert.

Joffe, a Hillary Clinton supporter who was expecting to land a top government cybersecurity post if she were elected in 2016, had compiled Internet data that he claimed indicated the Republicans’ nominee, Donald Trump, had a secret communications back channel to the Russian regime of Vladimir Putin, through servers at Alfa Bank, an important Russian financial institution.

Sussmann’s alleged lie occurred in September 2016, during the stretch run of the heated presidential campaign, when he brought Joffe’s data to the FBI and exhorted the bureau to investigate Trump. Sussmann is a former Justice Department cybersecurity lawyer; rather than tell the FBI’s Baker that he was working for the Clinton campaign, Sussmann insisted he was not representing any client, just trying to help the bureau protect the country.

The FBI did open an investigation, but quickly closed it upon finding the Sussmann/Joffe data to be specious. The prosecution’s first witnesses, FBI agents who assessed the data without knowing its source, explained that it appeared to be nonsensical and likely prepared by someone with an agenda.

Shaw explained the prosecution’s theory that Sussmann’s outreach to the FBI was designed “to create a sense of urgency” about the supposed Trump-Russia collusion threat that the Clinton Campaign was trying to peddle to the electorate.

Earlier, Sussmann had reached out to journalist Eric Lichtblau, then of the New York Times, to try to interest the Times in the Alfa Bank story. The campaign was frustrated that the Times didn’t move fast enough, so Sussmann tried to entice the FBI into investigating, which would raise the collusion narrative’s profile.

The Sussmann defense tried to paint a different picture. The evidence that Sussmann was working for the Clinton campaign is overwhelming, including law firm records that show he was billing his time on the Trump-Russia project to his then-firm’s Clinton Campaign account. So rather than try to refute what is undeniable, the defense is trying to parse it.

Michael Bosworth, the Sussmann lawyer who gave the defense’s opening statement, conceded that Sussmann was representing the Clinton campaign when he reached out to the Times, because the campaign wanted the Alfa Bank claims publicized. But, Bosworth maintains, that because Sussmann believed the Times was about to publish the story, he felt a sense of duty, as a former Justice Department official, to give the FBI a heads-up about the story.

This, the defense insists, was against the campaign’s interests because the bureau allegedly reached out to the Times to ask for a delay in publishing the story so agents could investigate.

Thus, the defense argues, Sussmann was representing the FBI’s interests, not the Clinton campaign’s. Bosworth says no one at the campaign specifically instructed Sussmann to contact the FBI.

Legally as well as factually, this defense is untenable.

Factually, Sussmann was consulting throughout the relevant time with his then-partner, Marc Elias, the chief lawyer for the campaign.

Obviously, it was in the campaign’s interest to entice the FBI into investigating. The public could then be told the allegations of a corrupt Trump-Putin relationship were so serious that the government was mobilizing to probe them. That is why elaborate preparation went into presenting the data package to the bureau.

Sussmann billed his time for the FBI meeting to the Clinton campaign. And the campaign has fought Durham’s information demands, citing the attorney-client privilege.

Legally, a client retains a lawyer precisely because the lawyer has knowledge and skills — in terms of protecting the client’s legal position — that the client lacks. The Clinton campaign retained Sussmann for his judgment, and he elected to go to the FBI because he judged it to be in the interest of his client’s desire to promote the Trump-Russia collusion narrative most effectively.

A lawyer can make incorrect judgments. In hindsight, a client may see the lawyer’s actions as backfiring and thus disserving the client’s interest. But that doesn’t change the stubborn fact that the lawyer’s actions were taken in the context of representing the client – including being compensated by the client, and having relevant communications shielded by the attorney-client privilege.

If what we heard Tuesday is really Sussmann’s defense, Durham must be smiling.

Andrew C. McCarthy is a former federal prosecutor.