If Brooklyn's dreams come true, there will come a night roughly two years from now when Mayor Bill de Blasio will take the podium at the 2016 Democratic National Convention and welcome delegates to his home borough.

We don't know if Brooklyn will get the DNC. What we also don't know—and what might be the more interesting question—is whether that hypothetical turn on the national stage will be a cameo for de Blasio and his progressive urban policies or part of a new, higher profile for America's cities that the mayor is already trying to cultivate.

De Blasio's sudden surge to victory last fall fueled optimism among progressives who have long hoped that cities might deliver the kind of policy victories Washington seems unlikely to ever again deliver. After two decades of Republican mayors in one of America's most liberal and Democratic cities, de Blasio had engineered a come-from-behind victory with a simple message critiquing economic inequality and demanding police reform—a resounding counter-attack against the trickle-down and law-and-order politics that have dominated national conversation since 1980.

As his transition unfolded in late 2013, de Blasio gave voice to a separate but related hope: That cities could once again become a federal policy priority, as they had been during the New Deal, during the Great Society and for a brief moment in the 1970s when President Carter walked through the rubble of the Bronx. De Blasio staked out a role as a “national convener” for a “progressive urban agenda.” Ahead of a meeting with other mayors and President Obama, he said he was beginning “a mission that I look forward to working with my fellow mayors … to slowly but surely turn the congressional focus in particular back to investments in education, infrastructure, mass transit, housing, the kinds of things that would change New York City so fundamentally.”

Meanwhile, progressive policies seemed to be getting a foothold in other cities as well. Boston elected Marty Walsh, who pulled together progressives and labor to win. Houston re-elected Annise Parker, noted for her green credentials and pro-immigrant positions. Seattle passed a $15 minimum wage. The Nation and American Prospect ran thoughtful articles hailing the potential for the rise of “the progressive city.”

But is this a blip on America's political radar screen or the kind of moment we'll look back on in 20 years as a turning point? A lot depends on the tall man in Gracie Mansion, and his counterparts in city halls nationwide.

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In August, de Blasio hosted mayors from around the country for a conference at Gracie Mansion, fulfilling a task given him by the U.S. Conference of Mayors to co-lead a “cities of opportunity” task force. In the gleaming sunshine, 33 city leaders like Chicago's Rahm Emanuel and Boston's Marty Walsh stepped out to sign a commitment to policy principles—higher wages, universal pre-K and municipal broadband. “We also agree,” the commitment read, “to work together to achieve federal action.”

The pairing of the mayors' promise of local action with their push for national change was about more than rhetorical symmetry. The limitations of the former necessitate the latter. While de Blasio has already used his powers to substantially change the orientation of policy in New York City—reining in stop-and-frisk, settling discrimination lawsuits, increasing the scope of the city's living wage law and improving sick-leave and welfare rules—there are mountains that cities can't climb without federal help.

“I think the real question is whether mayors, including de Blasio, have the tools to really address the inequality problem,” says Fordham University political science Professor Bruce Berg. “They clearly lack the resources to engage in wholesale redistribution; and in most cases, they probably also lack sufficient control over their own tax structure to bring about real change. This leaves them with policy tools such as pre-K, affordable housing, more equitable economic development, and job creation that can, at best, have an impact on inequality in the very long run.”

New York City, for instance, cannot under current state law set its own minimum wage. And de Blasio was unable to fund his signature universal pre-K program with a tax on the wealthy, as he'd hoped, because the state controls tax policy. Other cities are similarly constrained: An analysis by the National Employment Law Project found that at least 19 states prohibit localities from setting minimum wages. Even where cities can pursue ambitious policies, many would find it hard to do so without the resources—and even playing field—that federal policy can provide.

Calls for an urban agenda are nothing new. In 1990, Mayor David Dinkins convened a group of big city mayors to push for city-friendly federal policies. Two years later, after the Rodney King riots in Los Angeles, there was talk about a plan to address urban poverty; the talk was brief. Mayor Michael Bloomberg put his prestige and a slice of his personal fortune on the line seeking saner national immigration rules, more federal infrastructure investment and reasonable safeguards on gun ownership—noble efforts that produced few national policy victories.

But this is a different time. Real progressive leadership is in place. A real sense of economic crisis is still detectable. The right-wing diminishment of federal authority has paved the way for a multi-metro coalition. Progressives are at the table, and the stakes are high.

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What will determine if the de Blasio approach succeeds at winning progressive policies to benefit America's cities? Here are 10 factors that will matter.

1. Whether more big cities come on board: De Blasio's just getting started, but of the 33 mayors who signed the commitment letter in August, only 11 represent cities among the largest 50 in the country. To have political sway, the urban movement will have enlist more of the big cities, and more little ones, too—especially urban areas in red states.

2. Whether the policy wish-list becomes more urban: Nothing about pre-K or a higher minimum wage is particularly urban in nature; that doesn't make them bad ideas—they're great ideas—but the whole point of an urban agenda is that cities offer, and need, something unique. A true urban agenda will eventually address cities' transportation, infrastructure and public safety needs.

3. Whether it stays progressive: Broadband and UPK are good places to start precisely because they are relatively uncontroversial. Not only are they elegant ideas that make a difference in people's lives, they have elements that ought to appeal to folks in the center and even on the center-right. Real change may require picking additional targets that—like the prospect of hiking the minimum wage—face deeper opposition: criminal justice reform, immigration-rule changes and re-orienting federal transportation aid to favor mass transit over highways.

4. Whether de Blasio wins re-election: The mayor won't face voters again until 2017, but we'll know better by the DNC (wherever it is) whether he's likely to face a tough fight or enjoy a relatively smooth walk to second term. Progressives in the city and elsewhere seem to recognize that a lot is riding on whether de Blasio can defy the stereotype and prove that cities can be competently governed from the left. So far, unlike in the Dinkins years when Rudy Giuliani could be heard doing pushups to get ready for their electoral rematch, no obvious challenger to de Blasio has emerged. After a rocky first six months, the mayor has recently showed a steadier hand on day-to-day management. Notably, he went from being Andrew Cuomo's punching bag to becoming the governor's ambassador to the left, a valuable perch to occupy. Still, de Blasio's cakewalk against Joe Lhota last November shouldn't be taken as proof that a more competent campaign to unseat, with more money, might not capitalize on something like, say, the broiling resentment of the police unions.

5. Whether his partners survive, too: Some of de Blasio's allies in other City Halls are, like him, safe until 2017, but others face re-election next year. Not only is it important that his partners survive to remain in the coalition, it's also vital that they do so without the kind of knock-down-drag-out fight that might force a mayor to abandon—for the campaign season, or forever—more ambitious policy ideas like the ones that will drive an urban agenda.

6. Whether the local policies “work”: Well, duh. If the policies bomb, don't expect too many happy re-election endings. Beyond the campaign implications, though, the more successful the urban movement's programs are, and the faster they demonstrate that success, the easier it will be to get more mayors to join the push to convince the feds to come along. As soon as Giuliani's crime-reduction strategies began bearing fruit, other cities started to cop on. If UPK implementation goes well in New York, and if the Seattle minimum wage initiative reduces poverty and avoids any significant job losses, the lefty mayors will need a bigger stage for the next mayors' conclave at Gracie Mansion.

7. Whether anything crazy happens: New York City and the nation had a policy agenda on Sept. 10, 2001. Then it was shattered, and it was years before the smoke fully cleared. Even if de Blasio makes all the right moves, fate could deal a swift and decisive blow to his movement's prospects. It's not nice to think about, but you've got to factor it in.

8. Whether the mayors decide to play hardball: If all we needed were good ideas, capable leaders and passionate spokespeople to revive a national urban agenda, we would already have one. But power, not principle, is what gets things done—so the urban movement needs to figure out how to harness its muscle. De Blasio recognizes this: He told reporters at the Gracie Mansion gathering: “How do you move Washington? Well, I just say count. Count up the millions and millions represented by all these people, and look at the states they come from. And some of their senators and some of their congress members are not voting in the interest of these cities, they're not trying to address these issues. There has to be more consequence for that.” But it's unclear that the other mayors, or even de Blasio himself, will really be willing to rally city voters to demand better urban policies—by threatening to vote down senators and reps who don't deliver. What's more, it's unclear that someone playing that kind of hardball would win.

Doug Muzzio, a Baruch College professor and leading analyst of city politics, is skeptical. “I understand the logical argument. But a hard-boiled, realistic view of the prospect for increased federal involvement is that the odds are between slim and none,” he says. “In Texas, in the South, in the Southwest, even in the heartland, you don't have a progressive movement, you have the opposite. Sometimes it's important to tilt at windmills and maybe this is that time but it sure looks like tilting at windmills.”

9. Whether the GOP decides to play at all: The fact that most cities are unshakeable bastions of Democratic Party loyalty sets up an uncomfortable dynamic: Democrats can often afford to take cities for granted, while Republicans are usually justified in writing them off. This is not universally the case—Jack Kemp famously tried to cultivate an urban Republican platform, and many Democrats fight hard to earn urban loyalties—but the lack of real competition for cities as electoral prizes means their priorities play second fiddle to those of suburban moms or “heartland” (ugh, that word) farmers. An electoral opportunity or two might draw the GOP into the urban conversation. And wouldn't it be great if all those wealthy donors that draw presidential candidates and other heavyweights for big-city fundraisers made their checks contingent on action to help the cities? Oh, to dream.

10. If de Blasio avoids rumor of presidential ambitions: De Blasio is too smart to think he could be elected president, but mayors who develop a national profile are often touted as presidential timber, and this casts all their policy passions in an unhelpful light. Since John Lindsay's ill-fated run in 1972, Ed Koch, Giuliani and Bloomberg have all been considered—and probably considered themselves—White House material. If de Blasio succeeds in creating a movement but it appears attached to personal national ambition, it will fade from the scene when he does. And that would be very bad. Remarkably (sometimes frustratingly) well-disciplined on stage, de Blasio will do a good job of knocking down any idle thumb-sucking; his aides and advisers will have to be similarly unqualified in their disdain for any such chatter.

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If all those factors work out right, the potential so many sensed in de Blasio's 2013 victory could be realized. Sure, there are plenty of reasons to suspect it won't, but it's always easy to dash hopes. What's different already from any time in the recent past is that there's a real, actual chance for a national wave of urban progressivism. A little over a year ago, that's more than people thought fourth-place Bill de Blasio had.