The first two weeks of the trial of former Donald Trump presidential campaign chairman Paul Manafort on 18 counts of tax evasion and bank fraud charges have failed to implicate Trump or his campaign in any alleged criminal conduct.

Prosecutors working for Special Counsel Robert Mueller – who is investigating Russia’s interference in the 2016 presidential election – are expected to call their final witness Monday at Manafort’s trial in U.S. District Court in Alexandria, Virginia. If convicted on all counts, Manafort could face a maximum sentence of 305 years in prison.

So far we’ve learned that the prosecution’s star witness, former Manafort employee Rick Gates, is a liar, a serial adulterer and a thief who embezzled funds from Manafort.

And we’ve learned that Manafort is alleged to have evaded paying taxes on income that he and Gates earned through secret offshore bank accounts, shell companies and fraudulent bank loans.

But when it comes to the mandate given to Mueller on May 17, 2017, we’ve learned absolutely nothing. Mueller was charged with investigating “any links and/or coordination between the Russian government and individuals associated with the campaign of President Donald Trump.”

But neither Gates nor any other witness at the Manafort trial has testified about the Russian election interference or any alleged collusion between the Trump campaign – or Trump himself – with the Russians.

Manafort was with the Trump presidential campaign for just under five months. That’s a tiny sliver of the long career of the 68-year-old.

All of the testimony at the Manafort trial has addressed events that occurred long before Manafort went to work for 2016 Trump campaign. The testimony has focused on Manafort’s and Gates’s activities as alleged “unregistered agents” representing the Ukrainian government starting in 2006.

It would be absurd to argue that Manafort’s other clients in the 12 years since then are somehow to blame for any criminal activity he may have engaged in – and prosecutors aren’t even trying to point the finger at President Trump for these activities.

Manafort’s lawyers claim that Gates was the actual wrongdoer, and they subjected him to a punishing cross-examination.

Under questioning, Gates was forced to admit that he lied to the investigators from the special counsel’s office; embezzled huge amounts of money from Manafort and prior employers; and used the stolen funds in part to pay for extramarital affairs and a “secret life” that included an apartment and a girlfriend in London.

Through their cross-examination, Manafort’s lawyers pushed the idea to the jury that Gates got accountants to falsify Manafort’s tax returns in order to cover up the embezzling. Gates’ fraud apparently included submitting fraudulent personal expenses to the Trump inauguration committee.

Prosecutors tried to counter this with testimony by an FBI forensic accountant, an Internal Revenue Service agent, and Manafort’s own accountant. The accountant testified under a grant of immunity that although she worked with Gates a lot, she believed Manafort “knew what was going on.”

At a prior hearing in this case, the presiding federal judge – the very colorful T.S. Ellis III – said that Mueller is prosecuting Manafort in part because he wants Manafort to “sing” – in other words, testify against President Trump on other unrelated matters.

Ellis said at the earlier hearing that Mueller set out to “turn the screws and get the information you really want” from Manafort. And that information, according to the judge, is what “Manafort can give you that would reflect on Mr. Trump and lead to his prosecution or impeachment.”

It is certainly possible that Gates has some kind of evidence relevant to the Russian collusion allegation that Mueller has not yet made public. And perhaps Manafort also has similar evidence.

But so far at least, Manafort has chosen not to cooperate with Mueller. There was a hint of this in the trial with regard to Gates after the judge issued an order on Thursday at the request of the government. The order sealed portions of a “sidebar” conference the lawyers had with the judge to avoid “revealing substantive evidence pertaining to an ongoing government investigation.”

If Gates is the one with this “secret” evidence against the Trump campaign, the government will face a severe witness-credibility problem, given his embarrassing admissions on the stand in the Manafort trial.

Moreover, Gates admitted that he was threatened with 290 years in prison by Mueller’s team –but was promised he could get off with just probation if he agreed to testify against Manafort. That certainly gives Gates an enormous incentive to allege criminal conduct by Manafort. It’s hard to believe that prosecutors would offer Gates a “get out of jail free card” if he testified that Manafort did nothing wrong.

If Manafort is found guilty of tax evasion and bank fraud, some will try to use his very brief association with the Trump campaign to tar the president. But such criticism would ignore two crucial facts.

First, presidential campaigns are not law enforcement agencies. They have neither the capacity nor the resources to do detailed background investigations on the thousands of individuals who volunteer to work with a campaign.

Second, Manafort appeared to be a successful, ethical businessman. Even the government – including the IRS, the FBI and our intelligence agencies – had no idea that he was allegedly engaging in any wrongdoing for a foreign government through an elaborate scheme of offshore bank accounts and shell companies, until Mueller’s office started investigating him.

In an odd point in the trial, Gates testified that he and Manafort actually told the FBI about their offshore bank accounts in Cypress back in 2014. At the time, the FBI was investigating the former Ukrainian president. Gates and Manafort disclosed the accounts to the agent, because that is how the Ukrainian government paid them.

Yet the FBI apparently did nothing about this and did not notify the IRS. There has been no explanation from the government as to why it took no action at that time.

And surely the Trump campaign cannot be legitimately criticized for not knowing, as the federal government did not know, what Manafort and Gates were supposedly doing vis a vis their personal finances and income tax liability.

The bottom line is this: The Manafort trial is about alleged criminal activity by Manafort and Gates. If Manafort had not spent less than five months working as a volunteer on the Trump presidential campaign he might never have even been charged with a crime.

However, Manafort’s short time in a high-visibility role with the campaign placed all his past activities – having nothing to do with Donald Trump – under the microscope.

In the unlikely event Manafort had been charged with the same crimes but had never joined the Trump campaign his trial would no doubt have attracted only a small amount of media attention. Only his association with Trump has turned his trial into a major news story.

The Manafort trial is complicated. It is receiving enormous news coverage. Most Americans don’t have the time or interest to follow every detail on a daily basis. So it’s understandable that many people assume the trial has something or other to do with President Trump and his campaign.

But that assumption is a mistake. Whether you support President Trump or oppose him, the simple and indisputable fact is that nothing in the Manafort trial so far has revealed any evidence of collusion with Russia or any other misconduct by President Trump or his campaign.

This trial is about Paul Manafort and Rick Gates – not Donald Trump.