Beleaguered politicians like to complain they are too hemmed in by circumstances and handlers. If only they could throw off the shackles and be themselves, they would surely succeed.

President Trump is going through one of those moments now and the restraints are flying off before our eyes.

Look out, world — no more Mr. Nice Guy!

Trump’s decision to be more Trumpian is reflected in a flurry of personnel changes that signal shifts in policies, including his approach to special counsel Robert Mueller.

Asked what was behind one change, an insider described the president’s mind-set: “I tried it your way, and it hasn’t worked.”

The topic was a revamp of Trump’s legal team, where the feisty husband-wife team of Joseph diGenova and Victoria Toensing signed on and the more conciliatory John Dowd signed off. But the legal shake-up was just one example of how Trump is reshaping his presidency for the fights ahead.

Facing crises on several fronts, he is at a political and legal crossroads. With Mueller methodically probing every corner of his life and with women from his past grabbing headlines, the midterm elections are not looking good for Republicans.

Even more important, they are shaping up as make-or-break for Trump.

Impeachment is almost certain if Democrats take the House and even if they can’t fulfill the left’s dream of removing him, they will block his agenda. In that case, the spending bill the president reluctantly signed Friday would be a fond memory because he’ll never get one closer to his liking.

Trump’s frustrations run the gamut of policy and people. The departure of the perpetually unhappy Gary Cohn from the economic team was timely and the firing of Rex Tillerson as secretary of state was especially liberating.

Neither man was fully on board with Trump’s America First mantra and they weren’t shy about letting outsiders know. Trump was more patient with public dissent than most presidents would be, though he’ll never get credit for restraining himself for as long as he did.

Larry Kudlow, Cohn’s replacement, differs with Trump on tariffs, but was an early supporter and is a happy warrior for tax cuts and economic prosperity.

Tillerson’s planned replacement, CIA chief Mike Pompeo, is sure to bring a harder, more Trumpian edge to diplomacy. The same can be said for the president’s decision to replace Gen. H.R. McMaster as national security adviser with John Bolton.

Bolton is a lightning rod for the left and the Democratic media greeted his appointment with a screaming chorus of “hawk,” as if that’s a sin. In truth, Bolton is a hawk because the world is full of dangerous actors and some evil ones and he sensibly believes there’s no point of being America if we’re going to roll over and surrender our advantages.

Already there are rumblings that Russia, China and North Korea won’t be happy to see Bolton having the president’s ear — which proves Trump chose wisely.

Then there’s Iran. Trump has made it clear he won’t recertify the deeply flawed nuclear deal this year without major changes, and he’s not likely to get those changes because Europeans are leading the talks. Enough said.

Nor is Trump likely to keep tolerating Iran’s regional aggression when our most important allies and the most unlikely bedfellows — Israel and Saudi Arabia — are united in their desire to stop the mullahs. If this is not a coalition worthy of American leadership, what would be?

Each of these issues is perilous, but Trump has a new security sidekick who realizes that the status quo is more dangerous if America does nothing. Bolton, in spirit if not words, has always been an America First kind of guy.

But what does it mean for Trump to be Trump when it comes to Robert Mueller? My reading of the change in lawyers is that Trump gave up on Dowd’s idea that the way to handle the investigation was to cooperate with every request in the belief that, at some point, Mueller would concede he had nothing and close up shop.

That wasn’t a crazy idea initially and even throughout last year. But at this late date, with Mueller demanding Trump’s family business records and pressing the president to sit for an interview, there is no end in sight.

Trump’s decision to do it his way, meaning counterpunching with personal attacks, is captured in tweets, such as when he wrote: “Why does the Mueller team have 13 hardened Democrats, some big Crooked Hillary supporters, and Zero Republicans?”

Still, that’s fairly mild compared to the views expressed by diGenova and Toensing. He is a former federal prosecutor and she worked for Sen. Barry Goldwater, and both believe top officials within the FBI and Justice Department concocted the collusion charges against Trump for partisan reasons.

I basically agree with them, but it’s not clear how their belief will change the legal strategy in the case at hand, including whether Trump would agree to be interviewed by prosecutors. Dowd argued it would be a mistake and a perjury trap, but Trump said again last week that “I’d like to” meet with Mueller.

He probably will. After all, it’s his neck on the line and he believes he’s always his best defense, even when he’s not.

Blas-é on scandal

The late Mayor Ed Koch liked to say that if a sparrow dropped dead in Central Park, he would be blamed. Oh, for the good old days.

Now the current mayor is openly labeled a crook in federal court — and the only sound is silence.

Harendra Singh, a restaurateur and donor to Bill de Blasio, said in a Long Island trial that he steered thousands in bribes to the mayor’s campaigns — and got big favors in return.

For much of the city’s history, a charge like that would rock the political world and lead to calls for a new investigation. Instead, de Blasio was so blasé that he went on vacation and his Democratic colleagues went into hiding.

Clearly, we have the terrible government we deserve.

Honor heroes old and new

New York is in mourning after city firefighter Michael Davidson lost his life heroically in a Harlem blaze. He leaves behind four young children and a wife who is a cancer survivor.

The city also mourned in 1971 when Herman Bell murdered two police officers, yet Bell is now approved for release on parole. Officers Joseph Piagentini and Waverly Jones were lured to their deaths by Bell, a member of the Black Panthers who shot them in cold blood.

Heroes are forever, and just as their sacrifice has no expiration date, neither should our memory. Bell deserves to die behind bars.

Political orientation

Reader Donald Nawi is amused by the circus swirling around Cynthia Nixon’s challenge to Gov. Cuomo, writing: “We used to say ‘Our crooks are better than their crooks.’ Now, it’s ‘Our lesbian is more qualified than their lesbian.’ ”