If New York City Mayor Bill de Blasio joins the gaggle of Democrats running for president, he will stand out as the only one who flouted federal law so often and so flagrantly that prosecutors felt compelled to publicly explain why they had not gone ahead and locked him up.

The March 2017 statement by the U.S. Attorney’s office in Manhattan announced:

“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,” the statement reported.

Note the absence of the word “alleged.”

The pay-to-play operation—which involved everything from a contract for mint-scented, rat-resistant trash bags to multimillion-dollar real estate deals—is stated as fact. The statement goes on to explain why the prosecutor had decided “not to bring federal criminal charges against the Mayor or those acting on his behalf.”

“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,” it says.

Those “changes in the law” included a U.S Supreme Court decision in June of the year before, which vacated the corruption conviction of former Virginia Gov. Robert McDonnell, who had accepted a $175,000 loan and various gifts from a dietary supplement manufacturer that sought state assistance in testing and marketing his product.

The decision was written by Chief Justice John Roberts, who explained: “There is no doubt that this case is distasteful; it may be worse than that. But our concern is not with tawdry tales of Ferraris, Rolexes, and ball gowns. It is instead with the broader legal implications of the Government's boundless interpretation of the federal bribery statute. A more limited interpretation of the term ‘official act’ leaves ample room for prosecuting corruption.”

In short, just arranging a meeting in exchange for a gift does not constitute corruption under the more narrow definition. The accused must have performed an official act such as can be placed on an agenda or memorialized in the record.

That narrower definition of corruption came when the feds in New York were eight months into investigating de Blasio. They felt they were well on the way to making a case.

“The government was lusting, lusting to get de Blasio,” an attorney for a big donor who was repeatedly questioned by the feds told The Daily Beast.

But in instances such as the mint-scented rat-repellent trash bags, de Blasio had simply granted a meeting with parks department officials and facilitated a field test.

In at least one real estate transaction involving a restaurant lease, de Blasio seemed to have performed what might rightly be called an official act on behalf of a big donor.

The prosecutors convinced this particular donor to “flip.” The donor secretly pleaded guilty to what a felony complaint described as “the payment of bribes... in exchange for official acts” by de Blasio and agreed to testify against the mayor if called.

The problem for the feds was that the quid the donor tendered for the quo allegedly provided by de Blasio did not go into the mayor’s pocket.

The quid cash instead went toward bankrolling de Blasio’s political agenda, which ultimately is to further his personal ambitions.

And, as the feds said in their statement, there is a “particular difficulty in proving criminal intent” in corruption cases where the official in question personally enjoys no financial grain.

“ The government was lusting, lusting to get de Blasio. ”

Where he might otherwise have faced criminal charges, de Blasio is instead following his ambitions to a possible run for the president.

And if Trump is President Id, de Blasio would be President Quid.

Imagine the quos that could bring!

Any potential quo seeker put off by de Blasio’s progressive stances need only consider the flexibility he demonstrated back when he was first running for mayor. He made clear by his taxi cab policies that enough quid could make him happily compromise a principle or two.

Evgeny Freidman, the ”Taxi King” who was business partners with Michael Cohen, raised just under $50,000 for de Blasio. Yellow cab folks kicked in thousands more. And the supposedly progressive de Blasio came out against the green taxis that the city had begun licensing in the outer boroughs where minority folks have long had difficulty getting yellow cabs.

During that same first campaign, de Blasio also signaled a willingness to adjust his priorities. His union leader cousin funneled cash to folks who have long sought to ban horse-drawn carriages in the city. Those folks then mounted a million-dollar TV campaign slamming de Blasio’s prime opponent in the primary, City Council Speaker Christine Quinn.

De Blasio promised that he would move to ban horse-drawn carriages “on day one.” He might have succeeded had the wife of one of the carriage drivers not been a nanny for actor Liam Neeson’s kids. Neeson joined a successful effort to oppose the new mayor’s stated first order of business.

The biggest early de Blasio donor was restaurateur Harendra Singh, who was seeking a new lease on a city property in Queens even though he was more than $2 million in arrears on the rent. Singh was one of the most potentially damaging witnesses the FBI interviewed in its 18-month investigation of de Blasio.

In October of 2016, Singh secretly pleaded guilty to bribing de Blasio. A transcript of the proceeding was subsequently unsealed and was first reported by the New York Times.

“I gave these donations to the elected official in exchange for efforts by that official and other city officials to obtain a lease renewal from the city agency for my restaurant on terms that were favorable to me,” Singh told the judge.

Singh also admitted to bribing former Nassau County executive Ed Mangano, who was actually charged along with his wife, Linda, with corruption. Mangano was said to have accepted personal gifts such as a $7,300 watch—not a Rolex, but a Panerai Luminor—and holiday vacations in exchange for such official acts as bestowing on Singh a six-figure bread contract at the county jail.

Mangano’s attorney moved to have the case dismissed, contending that his client, a Republican, was the victim of “selective procession” because the feds decided “not to prosecute New York City Mayor Bill de Blasio, a Democrat, despite the fact that Singh pled guilty to bribing de Blasio.”

Federal Judge Joan Azracil denied the motion, noting, “The de Blasio case only involved campaign contributions and not personal gifts. This is critical because the government faces a more difficult standard in bribery cases involving political contributions, where the government must prove ‘an explicit quid pro quo.’”

The judge further found, “In addition to the legal hurdles involved in bribery cases involving campaign contribution, it may simply be harder to convince jurors to convict when the defendant is charged with accepting campaign contributions as opposed to personal gifts.”

The case ended in a mistrial after the jury foreman announced in a note that he could not continue for unspecified reasons. The case was retried and Mangano and his wife were convicted. They face maximum a sentence of 20 years.

In the meantime, the news site The City obtained via a Freedom of Information request a heavily redacted memo summarizing a Department of Investigation Report concerning fundraising for de Blasio's Campaign for One New York. The memo says de Blasio raised some $4 million before the nonprofit was shut down.

One conclusion that escaped redaction concerned an allegation that de Blasio solicited donations “from any individual who had, or whose organization had, matter pending before any executive branch of the city.”

“Substantiated,” the memo reported.

De Blasio has insisted he did nothing wrong. A spokesman told The Daily Beast: “These questions are asked and answered. Fundraising for the now-defunct Campaign for One New York—which supported Pre-K for All and the most aggressive affordable housing campaign in city history—was thoroughly reviewed by multiple parties and it was determined that the Mayor acted lawfully.”

“ We do everything by the law. ” — Mayor Bill de Blasio

And De Blasio has also insisted he is doing nothing wrong with his present fundraising for his new Fairness PAC. A spokeswoman noted remarks de Blasio made on WNYC in April.

“We do everything by the law,” the mayor said. “We are following the law to the letter. All decisions, and I’ve said this many times, and it is absolutely consistent, all decisions made by the administration are made on the merits, made on what’s in the interest of people in New York City.”

De Blasio has been assisted in his fundraising for the new PAC by lawyer Frank Carone, a longtime pal and Democratic party figure in Brooklyn. Carone represents what the New York Times called “a pair of notorious landlords” who recently sold the city a group of 17 buildings for affordable housing. The original appraisal was $50 million. The city paid $173 million.

The Fairness PAC has paid for de Blasio's exploratory trips to Iowa, New Hampshire, South Carolina, and Boston, where there was a fundraiser. De Blasio initially declined to name the host, which proved to be Suffolk Construction, which recently completed a construction project in Brooklyn.

The firm apparently hopes to do more in the city, if the panorama of the Brooklyn waterfront and lower Manhattan that appears on its website is any indication. Suffolk recently hired a de Blasio associate.

In the interests of actual fairness, it should be noted that some donors paid only because it was their only real hope of playing. They only wanted a reasonable chance.

Consider the Queens-based janitorial supplies distributor who invented and patented mint-scented rat repellent trash bags.

Joseph Dussich of JAD Corporation of America drew his inspiration from Italian-American gardeners in New York, who have long planted mint as a rodent repellent.

You would think the city Parks Department would have been open to consider at least testing his homegrown innovation. Dussich tried for a decade just to get a meeting, but got nowhere.

''We can't get to first base,'' he rightly complained in 2013.

Then, in late 2014 and early 2015, Dussich made two $50,000 contributions to to the Campaign for One New York, a non-profit that raised cash to further de Blasio’s political agenda.

Ten days after he made the second installment, Dussich got an an invitation to a private meeting with de Blasio at City Hall. A mayoral aide then connected Dussich with the Parks Department, which a month later gave him a $15,000 no-bid contract to test his Mint-X trash bags.

Not long after that, the city issued a request for bids for $3 million in EPA-registered, rodent-repellent trash bags that were Mint-X “or equal.” Dussich's company boasts of having “the world’s only EPA-registered, rodent-repellent trash bag,” so it seemed a lock.

But a New Jersey firm underbid Dussich. The consolation was that the winner has to buy Mint-X bags from him.

Complications threatened when the FBI took an interest in the Mint-X contract, among numerous other deals involving de Blasio donors. The agents may have been hoping to make Dussich himself a rat of the two-legged variety.

But Dussich had broken no laws. And nobody could rightly blame him for seeking no more than a fair chance from a supposed champion of fairness who in fact rigs the game for money.

De Blasio’s actions in a number of deals likely would have been enough to land him behind bars along with Mangano had the mayor taken gifts. He instead took contributions that would enable him to live out his very personal reality beyond the borders of the city he is presently sworn to serve.

To him, the mayoralty is not a job, but a position from which to take an upward step.

Meanwhile, the feds were left lusting, just lusting after the man who is now contemplating whether to run for president.