When New York City Mayor Bill de Blasio failed to endorse Hillary Clinton’s presidential campaign and appeared to call into question her progressive bona fides, it shouldn’t have surprised anyone.

Though he served as Clinton’s U.S. Senate campaign manager in 2000, de Blasio has been clear that he does not believe that the former secretary of state was pulled sufficiently to the left over the course of the Obama presidency.

“The Democrat should be willing to challenge the status quo,” de Blasio said in November of last year in the context of Clinton’s efforts to recast herself a progressive populist in the mold of Massachusetts Democrat Elizabeth Warren. “The Democrat should be willing to challenge wealthy and powerful interests and should marry that with a grass-roots organizing strategy that epitomizes the message.”

When asked if Clinton could be that challenging candidate, de Blasio said that the jury was out. “I don’t think we’ve had the opportunity to hear from her on this new (post-recession) reality,” he insisted. But he had. He simply didn’t like what he heard.

It was my belief that de Blasio, an honest if confused progressive, simply wanted to use his influence to push Clinton as far to the left as he could. Having served as the mayor of New York City for all of 15 months (and a “public advocate” before that), it struck me that there was absolutely no way that he could be convinced that he has the mettle to mount a winning primary campaign on a national scale, let alone a successful general election campaign. After all, it was only four months ago that thousands were calling on the mayor to resign after they believed that his anti-police rhetoric contributed to the assassination of two NYPD officers in Brooklyn.

It is hard to underestimate de Blasio’s capacity for self-delusion, but I might have done just that. According to The New York Post’s well-connected reporter Fredric Dicker, de Blasio is hoping to spark a draft movement that would lead his fellow progressives to draw him into a presidential race against Clinton.

“De Blasio’s hope, the operative said, is a ‘Draft de Blasio’ movement will develop among progressive activists over the next several months that will lead to the mayor being able to defeat Clinton in the primary elections next year in much the same way leftist Sen. George McGovern successfully challenged the initially front-running establishment Democratic candidate, Sen. Edmund Muskie, more than 40 years ago,” Dicker reported.

That’s a dubious precedent to cite. McGovern rode a wave of anti-war sentiment and the belief that he had been robbed of the nomination in 1968 to win his party’s nomination in 1972. Finally his party’s nominee, McGovern proceeded to lose 49 states to Richard Nixon. From de Blasio’s perspective, however, this is a perfect parallel. His campaign would be aimed at sending a message to the country rather than winning any tangible gains.

According to Dicker’s reporting, de Blasio’s will deploy all the tools that allowed him to overtake Democratic favorite and City Council Speaker Christine Quinn in the 2013 mayoral primary and apply them to the race in Iowa against Clinton.

The draft effort explains why de Blasio was accompanied last week on his “progressive” speech-making trip to Iowa by John Del Cecato, one of the nation’s most important Democratic communications strategists and the man responsible for the popular “Dante” TV spot that helped get de Blasio elected mayor, said the operative.

“Why would your ad maker be traveling with you in a non-campaign year? Why was he there with de Blasio in Iowa unless you’re trying for something bigger?’’ asked the operative.

For Del Cecato, an expert in Iowa politics and a longtime campaign adviser to President Obama, helping develop a draft effort for de Blasio may also be personal.

There is a hunger among Democrats to see a real primary campaign in 2016, but Clinton’s allies contend that partisan Democrats only want to see attacks against her blunted and her reflexes sharpened ahead of the general election. That’s a bit of wishful thinking on the part of Team Hillary. It would be folly to underestimate the left’s desire to see the Democratic Party nominate a figure with a record of hostility toward the financial community. Wall Street is ready for Hillary, but they would almost certainly balk at de Blasio, 2016.