The case that a prosecutor from the Trump administration brought against a lawyer with ties to the Democrats is going to trial.
The first case that John Durham, the special counsel, is working on involves a lawyer who is accused of lying when he told the FBI that Donald J. Trump might have ties to Russia.
In 2019, when the Trump administration sent a prosecutor to look for wrongdoing in the Russia investigation, President Donald J. Trump told his supporters to hope that the investigation would find a "deep state" plot against him.
Three years later, on Monday, the team led by the special counsel, John H. Durham, will start the first trial in a case that grew out of their investigation. The claims and counterclaims from the 2016 presidential campaign will be brought before a jury. But the case doesn't show that the F.B.I. did anything wrong. Instead, it paints the bureau as a victim.
The main question in the trial is whether or not Michael Sussmann, a cybersecurity lawyer with ties to the Democrats, lied to the F.B.I. in September 2016 when he told them he thought Mr. Trump and Russia might have cyber connections. The F.B.I. looked into the situation, which involved a server for an Alfa Bank with ties to the Kremlin, and found that it was not true.
When Mr. Sussmann set up the meeting, he told an FBI official that he was not working for anyone. Prosecutors say he hid the fact that a technology executive and the Hillary Clinton campaign were his clients to make the accusations seem more true.
The defense says that Mr. Sussmann did not represent them at the meeting. His lawyers say that the F.B.I. knew that he had worked for Democrats on issues related to Russia hacking their servers, and that later communications made it clear that he also had a client who had helped make the data analysis about Alfa Bank.
Even though the charge against Mr. Sussmann is narrow, Mr. Durham has used it to release a lot of information to make it seem like the Clinton campaign was involved in a wide-ranging plot to make it look like Mr. Trump was working with Russia.
The other case Mr. Durham is working on, which will go to trial later this year, also has this implication. It says that a researcher for the so-called "Steele dossier," a collection of opposition research about supposed ties between Mr. Trump and Russia that has since been discredited, lied to the FBI about some of his sources.
Both cases have something to do with Mr. Sussmann's old job at the law firm Perkins Coie. One of his partners, Marc Elias, was the general counsel for the Clinton campaign and had paid for opposition research that led to the Steele dossier.
The allegations about Alfa Bank and the Steele dossier didn't have much to do with the official investigation into whether or not Russia and the Trump campaign worked together. FBI agents started that investigation for other reasons, and Robert S. Mueller III, the special counsel who finished the investigation, didn't use either of them in his final report.
In his report, he said that there were "many connections" between the Russian government and the Trump campaign, but he did not charge anyone with the Trump campaign with a crime.
But people who support Mr. Trump have rallied around Mr. Durham's story, which is similar to Mr. Trump's claim that the whole Russia investigation was a "hoax."
Lawyers for Mr. Sussmann have also pushed back on prosecutors' broader claims about the series of events that led to his indictment. They have said that the Durham team is spreading conspiracy theories that are based on politics.
In light of this, most of the fighting before the trial has been about how far prosecutors can go from the main charge. Judge Christopher Cooper of the Federal District Court for the District of Columbia has put some limits on what Mr. Durham's team can show the jury. This judge was picked by President Obama.
Mr. Durham and his team have hinted in court documents that they think the Alfa Bank data or analysis may have been faked, but they haven't been able to prove it.
But the judge told Mr. Durham he couldn't show evidence or make arguments along those lines. He said that there shouldn't be "a time-consuming and mostly unnecessary mini-trial to determine the existence and scope of an uncharged conspiracy" unless there was proof that Mr. Sussmann had reason to doubt the data when it was given to him.
Still, the judge has given the prosecutors more freedom to call witnesses from the Clinton campaign, such as Mr. Elias and the campaign manager, Robby Mook.
The problem with Alfa Bank goes back to the spring of 2016, when it was discovered that Russia had hacked into the computers of Democrats.
That summer, as questions about Mr. Trump's relationship with Moscow grew, a group of data scientists found strange internet data that seemed to link servers for the Trump Organization to Alfa Bank.
Working with Rodney Joffe, an executive in technology and an expert in cybersecurity, they thought it might be a secret way to talk. Mr. Joffe, who was already a client of Mr. Sussmann's, told him about it, and Mr. Sussmann told reporters and the F.B.I. what he thought was going on. He also told Mr. Elias about it, and officials with the Clinton campaign seem to have known that he was trying to get reporters to write about it.
Mr. Sussmann called the F.B.I.'s top lawyer at the time, James A. Baker, to ask for a meeting to share the information. In a text message, Mr. Sussmann said that he wasn't doing it for a client but rather because he wanted to help the bureau. Mr. Baker is likely to be the main witness for the prosecution.
But Mr. Durham's team got billing records from a law firm that showed Mr. Sussmann had worked on the Alfa Bank suspicions for the Clinton campaign. The team said he lied because if the FBI had known about the political link, they might have handled the case differently.
Andrew DeFilippis, a prosecutor for Mr. Durham, said at a recent hearing, "The strategy, as the government will argue at trial, was to make news stories about this issue, about the Alfa Bank issue." "Second, it was to get the police to look into it, and maybe third, your honor, it was to get the press to report that the police were looking into it."
At the same hearing, a defense lawyer named Sean Berkowitz said that he would not argue that Mr. Sussmann told reporters about these allegations on behalf of the Clinton campaign. But he said the defense might say that Mr. Sussmann didn't think he was going to the FBI "on behalf" of the campaign or Mr. Joffe.
Mr. Berkowitz said that Mr. Sussmann had told Mr. Baker that he thought The New York Times was going to write an article about the Alfa Bank rumors, which was why he was reaching out.
"We expect to hear from the campaign that, even though they wanted an article about this to come out, going to the F.B.I. was not what they would have wanted before there was any press," Mr. Berkowitz said. "In fact, going to the FBI killed the press story, which was not what the campaign would have wanted."
Some things about that matter are still not clear. Mr. Baker has said that the FBI tried to get The Times to "slow down" on publishing. But news reports say that editors were not ready to publish that article, which was being written by reporter Eric Lichtblau. Six weeks later, the paper did publish an article that mentioned Alfa Bank.
Lawyers for the defense have also said that even if Mr. Sussmann had lied, it wouldn't have made a difference because the F.B.I. would still have looked into the claims. And they have said that, despite what he said at first, Mr. Sussmann was clear in later conversations that he had a client. Notes from an F.B.I. meeting with Mr. Baker in March 2017 show that the agency knew by then that he had one.
The defense has also asked Mr. Lichtblau to testify, even though he no longer works for The Times. A lawyer for Mr. Lichtblau has asked the judge to ask him only about his conversations with Mr. Sussmann and not about other confidential sources or journalistic matters. Anyone on Mr. Durham's team is likely to disagree with such a rule.