Reader Freda Barry objects to my view that President Trump’s errant words and deeds are testing the faith of his followers. She writes: “No, supporters of President Trump are not losing faith. We are, however, totally dismayed by the unrelenting attacks on our president from the corrupt media!

“Please don’t give up on us or the president we VOTED into office. We still pray that he will NOT give up, even under continuous assault.”

Her plea is obviously heartfelt, and others also invoked prayer in delivering similar messages. But while I haven’t given up on Trump, I am concerned about the state of his presidency.

Indeed, events in recent days added to my worry.

So much so that I believe Trump, having twice called the special-counsel investigation a “witch hunt,” must now discipline himself to avoid getting burned at the stake. He pulled off one of the great political upsets in history to get to the White House, but may need ­another miracle to finish what he started.

If that sounds too grim, consider the lay of the land and a possible scenario about what will happen ­between now and next year’s midterm elections.

The most important ­development is that Democrats have been rewarded for their wild accusations that Trump’s campaign colluded with Russia to meddle in the election. The “resistance” has morphed into wider calls for impeachment, including in Congress, without evidence that any crime was committed, let alone by Trump.

Yet despite the lack of known evidence, the appointment of Robert Mueller as special counsel raises the ante in dramatic fashion. The case is now considered a criminal probe and the White House has no control over where it goes. Even the GOP advantage in Congress will be neutered because criminal investigations take precedence over hearings.

That gives Democrats ­leverage and opportunities unthinkable just four months ago. Having demanded a special counsel, they will use the existence of one as proof that Trump must be guilty of something and noisily drown out any discussion of his America First agenda.

They aim to make the Washington circus the main focus and block Trump from making good on his promises to expand economic opportunity for middle- and working-class Americans. If they succeed, his twin failures will be their main argument in the 2018 elections.

Any honest analysis would say the Dems are off to a decent start. Already, the repeal of ObamaCare, tax reform and a military buildup have to be regarded as less likely now than they were just weeks ago. They’re not dead, but the odds are going in the wrong direction and congressional Republicans seem paralyzed.

In their efforts to stymie Trump and ultimately remove him , one way or another, Dems will be helped, as they have been so far, by rogue members of the permanent bureaucracy willing to leak government secrets. And most of the media will keep throwing their forces into the battle to destroy the president they loathe.

Those trends, playing out in feverish headlines that will serve as rallying calls for the anti-Trump movement, will not be lost on congressional Republicans. Many kept their distance from Trump from the start, and endless, savage attacks on him would make them increasingly less willing to support the president on controversial legislation.

Some won’t wait for policy differences to abandon him, either out of personal hatred (see Sen. John ­McCain) or in a bid to save themselves politically in swing districts.

Those dynamics could continue all the way to the midterms. Given past experience, the Russia probe will still be going on then.

The history of special counsels is that they always manage to find something, thanks to having no restrictions on time or money and how far afield they can go.

In that sense, Mueller’s interest coincides with Chuck Schumer’s. Keeping the ball rolling, even if nothing major turns up against Trump, would allow Dems to paint every day as Watergate. The drumbeat would energize the left and discourage conservatives.

Next year’s elections, then, could become life or death for Trump’s presidency. If Democrats take either house of Congress, they will open new areas of investigation and push them on prosecutors. And there will be no way to stop them.

Even if they fail at removing Trump, they will have set the stage for the 2020 presidential election. It is easy to imagine that a damaged incumbent, largely without a party and with little progress on major promises, would have a hard time winning a second term.

Admittedly, that scenario, while not the worst case, is far from the best. Here is a more optimistic view of how Trump can prevail.

Because his problems are more political than legal, politics is also the solution. It starts with presidential discipline, both in word and deed.

Trump must put aside his resentment over the decision by acting Attorney General Rod Rosenstein to name Mueller as special counsel. For one thing, there is little doubt that Trump’s sloppy handling of the firing of James Comey and his various explanations for it played a role in Rosenstein’s decision. And Comey clearly aims to get even.

For another, by continuing to express his resentment, Trump guides public attention to the probe and away from his agenda and achievements. He should accept the fact that he helped create the mess but can no longer control it and move on.

That dovetails with his best hope of keeping congressional Republicans on board — by behaving in ways that give them practical and personal reasons to stick with him. While his core supporters remain in his corner, the key to survival and getting big things done is to broaden his appeal so that GOP officials have to stay the course.

It is true, as Trump says, that he has major accomplishments already. Business and consumer confidence are up, illegal immigration is down and he is working on better trade deals.

His push to shrink regulations will spur job creation and his support for law enforcement and school choice represent key reversals of misguided policies he inherited. Neil Gorsuch was a superb Supreme Court choice.

The president is also making strides in repairing the damage Barack Obama’s worldview inflicted on our global standing and our allies. One area of agreement in the Mideast is that both the Israeli and Arab leaders Trump is seeing on his trip felt betrayed by Obama.

The bottom line is that some pieces of a successful presidency are in place, but the progress is fragile and could be swamped by the Washington circus. Trump’s goal must be to avoid any more hint of scandal and ­instability so he can earn enough support to finish the revolution he started.

If he can do that, everything is still possible.