Felix Salmon makes the very interesting and powerful case:
City-dwellers, as such, have almost no say in national politics, and invariably end up subsidizing the increasingly-anachronistic lifestyles of their rural compatriots ... While cities are nominally democratic, in reality the party-political makeup of their legislatures almost never changes: the national parties have effectively hijacked the local political process by using the power of their strong national brand ... Given the opportunity to elect mavericks who will push creative and innovative policies in the face of apathy from national political parties, the citizens of great metropolises like San Francisco, Chicago, New York, Toronto, London, Paris, Miami and Berlin have been very happy to elect maverick politicians as mayor. But even the most powerful and imaginative mayor tends to find a lot of party political opposition, both nationally and locally ...
In the absence of an urbanist political party, then, city-dwellers will probably never be the political force that they can and should be ... If you live in a big city, you will probably find yourself more in agreement with your neighbors—or even with city-dwellers on the other side of the world—than you will with rural members of your national political party. The big political parties are very wary about immigration, for instance; big cities live and thrive on immigration, and support it strongly.
Cities are also vastly ahead of the rest of the world when it comes to gay rights; they’ve elected far more than their fair share of openly gay prominent politicians, and act as the safe haven to which young gay people flock whenever they feel persecuted in their small towns. A high density of gay people in turn feeds creative industries and increases the number of people interested in revitalizing the urban centers which were bywords for poverty in the 1970s and early 80s, and which are now the one part of the overheated housing market which seems likely to survive the property crash. There are lots of other policies, too, on which city residents would tend to agree. They are generally “greener” than the population as a whole: more environmentally aware, more willing and able to implement eco-friendly initiatives from cycling to recycling. While they might support local farmers, they have no time for big subsidies to agribusiness. They are much more likely to support efforts to build and strengthen educational institutions, especially at the university level. And in general they love heterogeneity and freedom: they’re skeptical when politicians talk about social norms or try to impose any kind of censorship.
The whole story is here. Can it actually happen?
UPDATE: Arnold Kling weighs in:
I think that there is a general misfit between our political institutions and the direction of technology. Our institutions are still in the middle of the twentieth century, centralizing power, putting more and more resources into the same number of political hands. See my essay on the wealth controlled by politicians, reprinted here. Meanwhile, the rest of society is in the 21st century, featuring what Chris Anderson calls The Long Tail (I just finished Kindling the book. Much of its message seeped out before and after the book appeared, but it's still worth reading.)
Salmon is correct to suggest that urban voters are not well served by the current institutional setup. Perhaps a "horizontal network" of urban voters would have more in common than a territorial entity that embeds a city inside a province or a nation-state. But to me that is an argument against giving territorial monopolies to government units, and my guess is that Salmon didn't mean to go there.
UPDATE II: Ryan Avent joins the conversation:
I think the constituency is there, but creating a political identity that will resonate at the ballot box is more difficult than simply identifying a majority with shared interests. What’s needed is a catalyst, which might fundamentally shift the way that suburban voters think of themselves.
One candidate is high gas prices. Expensive gas will likely produce an inward migration sufficient to place a larger share of households in explicitly urban areas. It may also align the interests of suburban and urban voters on a number of important issues–transportation and infrastructure funding, for example.
But the real game-changer may be the candidacy of Barack Obama. I’m reminded of the fundamental shifts in voter identification that took place under Richard Nixon and Ronald Reagan, who solidified southern Democrats and suburban anti-tax voters, respectively, in creating large new political voting blocs. Sometimes, a compelling politician is just a compelling politician, who comes and goes without altering the underlying political landscape. But sometimes, a compelling politician can facilitate the consolidation of new political identities.
He certainly has the constituency. The question is, even if he wins, can he heal the deep, deep split in the US on this issue? The geographic divide is also a class divide. Can the party of a single class, that amounts to say 30-35 percent of the workforce, effectively govern a polarized America? Seems to me the core issue is how to begin to mend the divide?