President Trump gestures as he speaks during a rally on Thursday in Grand Rapids, Mich. (Anthony Lanzilote/Bloomberg News)
Opinion writer

President Trump’s rallies have always been a peek into his unhinged, angry soul — confirmation that he operates outside the bounds of civilized behavior and rationality. His Michigan performance on Thursday might have been his worst to date, but he’s certainly getting worse with time.

Trump is now consumed with vengeance and fury, convinced (without actually seeing special Robert S. Mueller III’s report) that it provides complete exoneration. The part wherein Mueller says he does not exonerate Trump of obstruction and news that Mueller compiled hundreds of pages of evidence aren’t going to slow him or his sycophantic chorus down.

In Michigan, he was especially toxic. The New York Times reported:

“After three years of lies and smears and slander, the Russia hoax is finally dead,” Mr. Trump declared. “The collusion delusion is over.”

In his first rally since the end of the 22-month investigation, the president gleefully disregarded the old saw about revenge being a dish best served cold. He came onstage hot and served up one scorching zinger after another, taking particular delight in ridiculing Representative Adam B. Schiff of California, who oversees the House Intelligence Committee, and other Democrats who have led calls to investigate Mr. Trump. ...

Mr. Trump has always peppered his speeches with “hells” and “damns,” but on Thursday, he crossed the line into cruder language.

“The Democrats need to decide whether they will continue to defraud the public with ridiculous [bulls---],” the president said.

In vilifying his opponents, Mr. Trump was not troubled by the fact that the 300-plus-page report by Robert S. Mueller III, the special counsel, has yet to be released, or that Attorney General William P. Barr, in his summary of Mr. Mueller’s findings, stipulated that the report did not exonerate the president, even if it did not find him guilty of conspiracy or of obstructing justice.

He mocked asylum seekers, scorned the media and insisted he was smarter and richer than his opponents. That’s odd, since he has gone to such lengths to hide his grades and his tax returns. His speech was littered with lies, about everything from the auto industry (no, car manufacturers are not pouring into the United States) to purported improvements to the Department of Veterans Affairs to his fanciful assertion he has a better health plan than Obamacare.

Whipped into a fury, the crowd chanted to lock them up (all Democrats? the media?). Pretty soon he’ll be demanding an inquest into the missing strawberries (apologies to Captain Queeg).

Meanwhile, the object of some of Trump’s attacks, Schiff, gave it back to the president’s apologists, pointing out that if playing footsie with Russians, lying to the American people about his Russian dealings and willingly accepting help from a hostile foreign power isn’t “conspiracy,” it’s horribly wrong, and that Trump’s critics were right to expose his mendacity:

Democrats should be absolutely delighted with Trump’s descent into Crazyland. Trump’s already abysmal rating with women will no doubt fall further as he plays the role of emotionally abusive ex-spouse. Many of them wouldn’t give this kind of character their phone number or leave their house plants in his care — let alone give him the nuclear codes for six more years.

Trump did not deliver a marvelous health-care plan (in fact, he threatens to leave millions without health coverage if his court case to invalidate the Affordable Care Act succeeds). He has started a trade war. Coal is still a dying industry. The sugar high from his mammoth tax cuts is already wearing off. He mocks climate change as the country drowns, burns and gets blown away by extreme weather.

If 53 percent of Americans, according to the Quinnipiac poll, say they are certain not to vote for him, they might soon have company. So-called “soft” Trump supporters’ disgust might rise as his emotional and intellectual state deteriorates. And if the economy no longer produces ample distraction, they might simply sit home and watch from afar as he and his party hurl themselves into political oblivion.

Democratic presidential candidates should say nothing about any of this. Not now, and very little later. Res ipsa loquitur — the thing speaks for itself. Maybe candidates occasionally will want to taunt and mock him, but they should let him and the media coverage of him remind Americans how frightening is his behavior. Democrats should remain problem-solvers — talking to voters about what solutions they have to real-life problems and remaining rational, optimistic and calm.

Presenting themselves as a sane alternative to Trump should be the Democrats’ goal. And in that regard, Trump is doing more than they ever could to convince people outside the Fox News cult that he cannot manage himself, never mind the country.