For some, the most compelling thing about the Paul Manafort trial now going on is the former Trump campaign chairman’s penchant for absurdly expensive yet comically ugly clothing, which prosecutors are introducing into evidence to show the high-flying lifestyle he lived while paying suspiciously little in taxes. But judging by President Trump’s public comments and tweets (“He worked for me for a very short time. Why didn’t government tell me that he was under investigation. These old charges have nothing to do with Collusion – a Hoax!”), the case is a source of profound anxiety.

This trial, happening in Virginia, is only the first of two Manafort faces; he’ll be tried later in D.C. on separate charges. But we can already be pretty sure of what Trump will say when this one is over. If Manfort is acquitted, Trump will say it proves that he, Trump, is innocent of any and all charges related to Russia’s attack on our election system in 2016, and that Robert Mueller’s investigation is nothing but a witch hunt. If Manafort is convicted, on the other hand, Trump will say that it proves absolutely nothing, because the trial wasn’t about collusion with the Russians, and besides, Trump barely knows the guy.

In other words, if Manafort wins, the trial was incredibly important, but if he loses, it was meaningless. You might argue that Democrats are going to say just the opposite, but that isn’t exactly true. If Manafort is acquitted, they will indeed say that it doesn’t prove much of anything about the broader Russia investigation, because the investigation goes far beyond Manfort. But if Manafort is convicted, they won’t say it proves Trump is guilty, because this trial does indeed not have much to do with the 2016 campaign. And regardless of the outcome, what we’ve learned so far shows that Manafort should never have gotten within a mile of a major party nominee’s campaign, much less been tapped to run it.

After all, we’re talking about someone whose major client was a corrupt Ukrainian politician with close ties to the Kremlin. Who was allegedly millions of dollars in debt to a dangerous Russian oligarch. Who even in the sometimes-sketchy world of Washington lobbying was long known for being utterly devoid of ethics or morals. And who offered to work for free. Despite all these red flags, Trump has been trying to argue both that it was perfectly reasonable for him to hire Manafort because he had worked for other Republicans in the past and that he had almost nothing to do with him. Here’s what he said about him a few weeks ago:

“You know, Paul Manafort worked for me for a very short period of time,” Trump said, before ticking off other Republican presidential nominees with whom Manafort has been affiliated. “He worked for Ronald Reagan, he worked for Bob Dole, he worked for John McCain or his firm did. He worked for many other Republicans. He worked for me for what? For 49 days or something? A very short period of time.”
In fact, Manafort served 144 days as Trump’s campaign chairman.

Not only that, Trump and Manafort go way back. When Manafort and his partners, including longtime Trump adviser Roger Stone, set up their consulting firm in the 1980s, their first client was none other than Donald Trump. And let’s just say both of them have reportedly spent time interacting with the world of Russian oligarchs and mobsters.

But Trump’s real fear is not so much that a Manafort conviction on charges like tax fraud will reflect specifically on him, but that it will go a long way in the public’s mind to validate the Mueller investigation. You could argue that it’s already more than validated, given that Mueller has gotten guilty pleas from multiple Trump aides (Michael Flynn, Rick Gates, George Papadopoulos) and indicted dozens of people on charges related to Russian meddling. But a conviction of Trump’s campaign chairman, even if it’s on charges related to what he was doing before he joined the campaign, will make it even harder than it is now to claim that the investigation should never have begun in the first place and should be shut down immediately. Or as he said Thursday, “Now we’re being hindered by the Russian hoax. It’s a hoax, okay? I’ll tell you what, Russia’s very unhappy that Trump won, that I can tell you.”

And that — the investigation completing its work and putting everything it has learned before the public, both in the courtroom and in some kind of report that winds up getting released publicly — is what has Trump so worried. It’s almost as though he doesn’t want the public to know everything he and the people who worked for him did.