Mayor Michael Bloomberg's immediate legacy will apparently be one for which he would never have wished in his darkest nightmares: a high-profile, nationally engaged advocate for populist economic reform.

On Friday, New York City Mayor-elect Bill de Blasio visits the White House, a visit that Capital New York suggests shows that he is "already embracing his role as a national spokesman for progressives, particularly on the issue of income inequality." This is de Blasio's assumed mandate, addressing the rich/poor gap encapsulated in his campaign pitch of the "two cities" of New York. It's one that's again resonant with President Obama, who earlier this month declared income inequality the "defining challenge of our time."

This is not what Michael Bloomberg would like America to talk about, but it's his own damn fault. Bloomberg, who at this moment is at once both the richest man in and the mayor of New York City, railed against de Blasio's insistence on addressing inequality as the mayoral campaign unwound. After complaining that de Blasio's opposition to stop-and-frisk was racially motivated, Bloomberg used an interview with New York to assail the "two cities" concept.

The way to help those who are less fortunate is, number one, to attract more very fortunate people. They are the ones that pay the bills. The people that would get very badly hurt here if you drive out the very wealthy are the people he professes to try to help. … He’s a very populist, very left-wing guy, but this city is not two groups, and if to some extent it is, it’s one group paying for services for the other.

It doesn't require much psychological digging to figure out Bloomberg's motivation here: Bloomberg is a self-made bajillionaire who has done little to address the city's position as one of the most unequal places in the country.

But it is in part because Bloomberg did nothing to reel in the almost-tangible schism in the city that de Blasio was able to win this year's mayoral election. Twelve months ago, the smart money was on City Council Speaker Christine Quinn to take over as mayor, based on her robust base of support and years of public service. Over the summer, the race quickly became a referendum on Bloomberg — on the mayor's arm-twisting third term, on his police policies, on the economics of the city — and Quinn, a tactical ally of Bloomberg's in 2009, was unceremoniously rejected. As Quinn stumbled and Weiner weinered, de Blasio was there saying what everyone already wanted to hear. He won because people didn't like Bloomberg. Bloomberg ensured de Blasio would be mayor.

AP

Bloomberg did more than that. Mayor of New York is always a position that assures a fairly large soap box; Bloomberg's predecessor Rudy Giuliani was hardly a demure, unknown person. But Bloomberg used his bank account to ensure that he had soapboxes to stand on wherever he went on any issue. He was a loud voice on smoking, on trans fats, on sugar, on gun control, on gay marriage, and, eventually, on stop-and-frisk. By funding organizations that advocated on his positions and blanketing the media with press events and blog posts, he ensured that the role of the mayor of New York in effecting change was known and accepted. Giuliani's activism was mostly by example. Bloomberg's was by press release. And in doing so, he elevated his job — and de Blasio's — to a position from which national edicts are expected to be issued.

There are legitimate questions about the extent of de Blasio's actual progressive streak. He's no longer the leftist radical of his youth; during the campaign, he was blitzed from the left for supporting development and sniffing at bike lanes. Whether or not he can address inequality in New York City — which relies to a large extent on tax reforms passed at the state level — was the subject of a New Republic piece earlier this year. But that largely doesn't matter. De Blasio, like Massachusetts Sen. Elizabeth Warren, is now a figurehead for progressive policy advocacy. That's the welcome he'll receive at the White House.

Bill de Blasio will never have the bank account that Bloomberg leveraged to assure that he had at least some shot at getting his way (a point made by BuzzFeed's Ben Smith). But if de Blasio has his way, leveraging his national position to ensure change in Albany or Washington, Bloomberg might not have that bank account either.