Five associates of Trump have been convicted as a result of the Mueller investigation.

The old joke that absence of evidence is proof that the conspiracy is working is no longer a joke, and no longer old.

Attorney General William Barr’s summary of the Mueller report stated that it did “not establish that the President was involved” in collusion with Russia to interfere with the 2016 elections.

This seems on first reading to be a fairly straightforward statement that the president was innocent of collusion. But what is this conclusion based on?

The investigation into Russian collusion was impeded every step of the way by the president’s public actions, which may have prevented relevant facts from emerging.

The fact that Mr. Trump and his associates have been able to leave no fingerprints at the scene of the crime does not prove that no crime was committed, nor that he is innocent.

To many of us who have followed this story, Mr. Barr’s conclusion is incredible. Despite Mr. Barr’s statement to the contrary, there is a significant amount of circumstantial evidence that Mr. Trump and his associates worked with Russia to manipulate the 2016 presidential election.

According to the Mueller report, the Russians made multiple attempts to contact the Trump campaign, and we know that at least Donald Trump Jr. was very eager to accept their aid when he responded to a request for a meeting to discuss “dirt on Hillary.” “I love it,” he replied.

The result was the famous Trump Tower meeting of June 2016 in which the president’s son, Donald Trump Jr.; Trump’s son-in-law, Jared Kushner; and his campaign manager, Paul Manafort, met with four Russian operatives. President Trump subsequently advised Mr. Trump Jr., to lie about the purpose of that meeting, stating that it was about adoption policy.

We know as well that a large number of Mr. Trump’s advisers, including Mr. Manafort and Michael Flynn, his national security adviser, had numerous meetings with Russian operatives before the election, and that they lied about those meetings.

Mr. Manafort is also charged with giving Republican polling data to a Russian operative. This data could have been used by the Russians in their social media campaign to influence the 2016 election.

In addition to the secret meetings that Mr. Trump’s advisers had with Russians, we should add President Trump’s own secret meetings with Russian President Vladimir Putin (five according to the New York Times), at which no American officials other than Mr. Trump were present, and in which the translator’s notes were confiscated.

So far, five associates of Mr. Trump have been convicted as a result of the Mueller investigation, while others are facing trial on charges related to the Russian investigation.

From the investigations, it is clear that the Russians wanted to work with the Trump campaign, and the Trump campaign wanted to work with the Russians, and they each had ample opportunity to do so. Eventually, we may know much more.

The case against Mr. Trump for obstruction of justice is equally compelling.

The evidence for this starts with Mr. Trump asking the director of the FBI, James Comey to “let this go,” meaning the investigation of Michael Flynn.

Ultimately, Mr. Flynn pleaded guilty to obstruction of justice relating to the Russian investigation.

By then, however, Mr. Trump had fired Mr. Comey, publicly stating two times that he did so because of the Russian investigation.

Add to this Mr. Trump’s frequent criticism of the Mueller investigation and his attempts to impede its work, most clearly by refusing to testify in person with Mr. Mueller’s investigators.

And, add to this his dismissal of his attorney general, Jeff Sessions, related to Mr. Sessions’ recusal from oversight of the Russian investigation.

Finally, there is overwhelming evidence that Russia received benefits from their support of Mr. Trump in the 2016 election including: the relaxation of the Russian sanctions on some of Mr. Putin’s key associates; the weakening of a statement on Ukraine in the Republican Party campaign platform in 2016; Mr. Trump’s consistently siding with Mr. Putin, most notably his agreeing with Mr. Putin (in Helsinki) that Russia did not interfere in the 2016 election, despite the conclusions of the U.S. intelligence community.

And, most importantly, Mr. Trump’s lack of support for NATO and the weakening of our ties with our traditional allies in Europe.

William Barr’s report unfortunately leaves many of the most important questions raised by the specter of Russian interference in the 2016 elections unanswered.

That is why Congress and the courts must continue to aggressively investigate these issues, and why the full Mueller report must be made public.