Since the opening of the Donald Trump’s New York trial — when the former president’s counsel told the jury that the prosecution’s star witness “cannot be trusted” — the defense has telegraphed its principal strategy: Eviscerate Michael Cohen.

As Trump’s fixer and attack dog at the time of the alleged crimes, Cohen was more central to the events spelled out in the indictment than anyone in the defendant’s orbit. He even fronted his personal funds to quiet Stormy Daniels, who was shopping a story of a 2006 sexual liaison with Trump.

And having pleaded guilty to tax evasion, false statements and campaign finance violations related to the Daniels affair, along with a separate plea to making false statements to Congress, he seems tailor-made to be accused of lying to settle scores with his former boss. For the loyalty-obsessed Trump, moreover, the prospect of savaging a traitor promises additional psychological rewards.

But before the jury has even heard from Trump’s bête noire, the prosecution has made great strides to neutralize any plan to undermine Cohen’s testimony.

They have done so first and foremost by presenting a wealth of evidence that prospectively corroborates what Cohen will say. (And after his grand jury testimony and numerous reported sitdowns with the district attorney’s office, the prosecution knows what Cohen is going to say down to the last comma.)

The prosecutors’ decision to introduce their story through David Pecker, the former chief executive of the company that owned the National Enquirer, worked beautifully. A sort of Runyonesque rascal in his business affairs, Pecker came across as completely forthcoming on the stand. And he came forth with many details that involved Cohen and will be echoed by him. Those particulars included a key August 2015 meeting in which Pecker said he first promised Trump that he would smother the stories of his purported former sexual partners who might come forward now that he was a presidential candidate.

Every major witness since Pecker has also covered ground that Cohen will retread. By the time the jury hears the account of Trump’s onetime fixer, it will ring familiar in almost all its particulars.

Almost but not quite all. Only Cohen and Trump could have been privy to certain details of the alleged falsification of documents, the basis of the 34 criminal counts in the indictment.

Still, the district attorney will be able to respond to the defense’s ferocious attacks on Cohen by noting, in time-honored prosecutorial form, that the jury needn’t rely on his word alone because of all the corroboration.

In fact, the prosecution’s case has been sprinkled with disparaging characterizations of Cohen by its own witnesses, who have called him a “jerk” and worse. It’s another signal that the district attorney will argue that the case does not stand or fall on Cohen’s testimony.

And much of what follows Cohen will reinforce his testimony. Longtime Trump aide Hope Hicks figures to provide devastating corroboration of Cohen’s testimony about “the Boss,” including her firsthand account of the 2015 meeting.

The extensive corroborating evidence is just one way the prosecution is cutting off the defense’s main line of attack. As important, prosecutors have constructed and reinforced a narrative that bolsters Cohen’s story. It moves from the initial meeting, through the efforts to “catch and kill” the stories of a Trump Tower doorman and a Playboy model, and then to the critically important “Access Hollywood” tape that left the Trump campaign in an existential crisis.

The recording, which surfaced shortly before the election and caught Trump boasting of sexually assaulting women, prompted Republican Party leaders such as John McCain to withdraw their support for Trump. The jury heard evidence on Friday that key players in the catch-and-kill scheme were confident that Trump could not recover from the revelation.

Enter Daniels, who had recently resumed her efforts to parlay her alleged affair with Trump into a payday. If the campaign was on life support, her account threatened to pull the plug.

The story that prosecutors have presented from multiple sides thereby leads to the conclusion that the dealings with Daniels could have had only one motivation: to salvage the campaign. And that meant that Daniels not only had to be paid off but also that the purpose of the payoff had to be hidden.

The force of this account has Team Trump staring up at a nearly insurmountable incline. It’s not just that Cohen’s explanation of Trump’s alleged scheme and purposes will be roundly corroborated by other witnesses; it’s that no other explanation would make any sense of the whole patchwork of evidence.

The prosecution’s marshaling of that evidence leaves the defense with no viable counternarrative. Assume Trump’s team beats Cohen up for days on cross-examination and reiterates in closing that he can’t be trusted. What alternative story can they offer to supply a reasonable doubt about the district attorney’s account?

As Pecker testified and we will probably hear repeated at closing, Cohen couldn’t buy lunch without Trump’s approval. Is it remotely possible that he would nevertheless take out a home equity loan and pay Daniels $130,000 without Trump’s knowledge and direction? The Manhattan jury might be expected to conclude, in a word, “Fuhgeddaboudit.”

That’s not to say that the prosecution is coasting toward a guilty verdict or that the jury’s response to Cohen won’t matter. The charges of falsifying business records are still vulnerable to technical challenges involving intent and other questions. Especially with two lawyers in the jury’s ranks, stitching up that part of the case could be difficult. But with a broader rejection of Cohen’s testimony looking unlikely, the defense’s options for preventing a conviction are dwindling.

Harry Litman is the host of the “Talking Feds” podcast and the Talking San Diego speaker series. @harrylitman