Ed Reed/Mayoral Photography Office.

The mayor at a town hall in Manhattan on Wednesday night.

Sometimes it really seems like Bill de Blasio can’t catch a break.

He defies the tabloid doomsayers, slashes the number of arrests the cops make, sees crime fall to new records, yet still has to deal with charges that his ideology has endangered the city. He settles dozens of way overdue labor contracts and launches a massive universal pre-kindergarten program but is slurred as a lazy manager. He creates a municipal ID program with just shy of a million signups and secures a two-year rent freeze for 2 million tenants but gets dissed for his gym habits.

He learns on Thursday that neither state nor federal prosecutors are going to charge him or his aides, but receives an exoneration so qualified it basically writes the television ads his opponents will air against him later this election year.

Why doesn’t de Blasio get a break? Because his opponents to the right are too threatened by what he represents to miss a chance to belittle him. And because his erstwhile allies on the left believe that they have a right to expect more.

De Blasio was never accused of doing anything for personal profit. Unlike Sheldon Silver, whose outside legal earnings were tied to favors he executed as state Assembly leader, or Dean Skelos, who used his state Senate presidency to snag a juicy job for his son, or most of the many other NY pols who have done a perp walk in the past decade, no one ever said de Blasio had pocketed anything.

Instead, the DA investigated whether he or his aides had broken campaign-finance laws in an effort to win the State Senate back for the Democrats and the U.S. attorney looked into whether de Blasio or his people had illegally done favors for people who donated to a nonprofit he’d set up to push his progressive agenda.

“We have conducted a thorough investigation into several circumstances in which Mayor de Blasio and others acting on his behalf solicited donations from individuals who sought official favors from the city, after which the mayor made or directed inquiries to relevant city agencies on behalf of those donors,” acting U.S. Attorney Joon Kim wrote in a statement released Thursday. “In considering whether to charge individuals with serious public corruption crimes, we take into account, among other things, the high burden of proof, the clarity of existing law, any recent changes in the law, and the particular difficulty in proving criminal intent in corruption schemes where there is no evidence of personal profit. After careful deliberation, given the totality of the circumstances here and absent additional evidence, we do not intend to bring federal criminal charges against the mayor or those acting on his behalf relating to the fundraising efforts in question.”

Manhattan DA Cyrus Vance, meanwhile, informed the state Board of Elections via a letter that “this office has determined that the parties involved cannot be appropriately prosecuted, given their reliance on the advice of counsel”—a reference to the fact that de Blasio and his aides had received legal advice that a scheme to evade contribution limits by having donors give not directly to candidates but to county committees that then shared the money with the candidates was kosher. Since the de Blasio operatives thought they weren’t breaking the law, the logic goes, they can’t have broken the law.

Vance hastened to add: “[T]his conclusion is not an endorsement of the conduct at issue; indeed, the transactions appear contrary to the intent and spirit of the laws that impose candidate contribution limits, laws which are meant to prevent ‘corruption and the appearance of corruption’ in the campaign financing process.”

The prosecutors’ statements were far from an exoneration of the mayor. As with the James Comey press conference this summer on the Hillary Clinton email investigation, where the FBI director’s harsh language about the Democratic nominee made bigger headlines than his decision not to charge her, the Kim and Vance statements could be used as evidence against de Blasio in the court of public opinion.

That’s a little worrying: Prosecutors aren’t supposed to be the arbiters of right and wrong. They’re supposed to charge and try people for breaking the law and leave those whom they don’t charge alone. It’s dangerous to invest those offices with some deeper wisdom or authority to pass judgement on the people we duly elect to lead us.

No Backspace is City Limits' blog featuring a recurring cast of opinion writers passionate about New York people, policies and politics. The views expressed here aren't necessarily those of City Limits. Click here to read more.

De Blasio will, however, very likely be elected again. The smart money was already on him, and today’s news tilts the odds even more in his favor. As Bradley Tusk, the former Bloomberg adviser who has been recruiting Democrats to run against de Blasio, said Thursday, “Although the city deserves far better than this, the people best positioned to succeed in a Democratic primary are now unlikely to run, and we should therefore expect four more years of Bill de Blasio.” Paul Massey, the Republican real-estate magnate best positioned to challenge de Blasio in November, warned on Thursday that he’ll be reminding voters about the corruption investigation as the election approaches. Massey has the money and time to make inroads against the incumbent but he faces a huge registration disadvantage in a city where—with Donald Trump taking a jagged axe to the ideals and programs New Yorkers hold dear—the Republican brand is a concrete block sinking in the deepest part of the East River.

“We have been confident from the moment these reviews began that the actions of the mayor and our administration have always been within the law. The United States Attorney and Manhattan District Attorney have now put to rest any suggestion otherwise,” said Eric Phillips, a City Hall spokesman, in a statement. “We thank these prosecutors’ offices for conducting what were clearly diligent and exhaustive reviews – and for making public the conclusions of these probes. New Yorkers deserve honest, progressive government. With this mayor, they will always get it.”

The prosecutors have spoken, and the court of public opinion will render its decision in under eight months’ time. Yet neither one is really equipped to answer the deeper question of whether what de Blasio did was right. It’s not a simple question: De Blasio’s defenders will argue that he only did what many other officials have done, and that he had even more justification to do so given the enmity he endured from some powerful players from day one. A noble mission, they’ll say, requires a street fight now and then.

But while being a progressive doesn’t have to mean going limp or turning the other cheek, it does require recognizing that the principles behind campaign finance laws are worth defending as much as other beliefs, and that the mere appearance of impropriety can undermine the faith in government that is indispensable to the progressive program. Is that standard of conduct fair, when the Mike Bloombergs of the world can spend as much as they want and forever be deemed “incorruptible”? No. But progressives have to accept that they will be graded—by their own allies—on an exacting curve.

The mayor’s own actions over the past several months suggest a recognition that, while never breaking the law or even breaking from what might be standard political practice, he miscalculated the tradeoff between means and ends. As his 2017 campaign has ramped up, de Blasio has been seeking smaller donations. He long ago ended the Campaign for One New York nonprofit that was at the center of the allegations about quid pro quos.

On those scores at least, he is closer today to the mayor progressives deserve than he was before. That’s not much of a break, but it’ll have to do.