The Paul Manafort trial is giving us a chance to witness the effectiveness of Robert Mueller’s team, and I’m a bit worried at what we’re seeing.

The prosecution’s star witness, former Manafort associate Rick Gates, has been established as a thief, an embezzler, a liar and a manipulator.

And that’s all according to the prosecution. The defense managed to add that he was a serial adulterer.

Granted, the Mueller team will probably back up Gates with bank records and receipts for the many luxury items Manafort purchased with his ill-gotten gains. Prosecutors will also have hard-copy records of wire transfers and other money laundering.

But this still isn’t the first impression you want to make if you’re eventually going to go one on one with the president of the United States.

Trump and his operatives are going to jump all over Mueller’s use of a criminal-turned-snitch as proof that the special counsel is acting like a renegade D.A. in a crime movie.

Team Trump is already saying Mueller doesn’t have a real case against the president and is trying to lure our congenital liar in chief into a perjury trap.

Look for Trump and his lawyers to point to the Manafort case — and the prosecution’s reliance on a dodgy snitch — as they bob, weave and duck a presidential sit-down with the special counsel.

A suggestion: If President Trump continues to attack the media as the enemy of the people, let’s do what Dr. King did with the buses in Montgomery.

Boycott him. No reporter or news organization should show up for the White House briefings or for his appearances. Little of value comes out of them anyway.

All the reporters assigned to the White House could be reassigned to cover the federal agencies where the action really is — the ones that are implementing Trump’s avalanche of executive orders.

White House press secretary Sarah Huckabee Sanders would probably welcome it. No longer would she have to embarrass herself by being asked about facts and having to respond with Trump’s fantasies.

Driving in style: I see the Sacramento Bee found out about the little-known Department of Motor Vehicles office in Sacramento that caters to lawmakers, their staffs and other officials who can’t be bothered with the lines the rest of the public has to endure.

What the Bee didn’t report is that back in the day, when a lawmaker was too busy to make the trip, a DMV clerk would make an office call.

Movie time: “The Spy Who Dumped Me.” You may want to dump this movie. There are some funny exchanges between Mila Kunis and Kate McKinnon, but the antics get old after 15 minutes. Unfortunately, there’s still an hour and 45 minutes to go.

A proper send-off: Former John’s Grill owner Gus Konstin’s memorial service was a San Francisco historical tour de force. Every generation that lived, worked or patrolled here in the last several decades was represented.

Former Mayor Frank Jordan and current Mayor London Breed were on hand, as was the biggest contingent of police this side of a Starbucks.

Gus knew he was dying, and the priest said he’d asked him whether he had any requests for the service.

Gus replied, “Make it short.”

It wasn’t, nor should it have been.

My favorite story was told by Breed. She recalled having lunch years ago with Gus when she launched her first campaign for supervisor. She was blown away when he cut her a $250 check — it was the biggest contribution she’d ever received.

Then she showed it to Gus’ son John, who took one look and said, “What a cheapskate! It was supposed to be for twice that.”

Smart move: Former state Senate President John Burton came up to me at the Transbay Transit Center ribbon-cutting with a novel suggestion on how our friend Rep. Maxine Waters should respond to President Trump’s comment that she has an “extraordinarily low IQ.”

“Have her publicly challenge him to an IQ contest — and offer to spot him 20 points.”

Want to sound off? Email: wbrown@sfchronicle.com