Just take a look at these maps.
Now that we know President Obama managed to win decisive victories not just in the Electoral College but also likely in the popular vote, much of today will be spent figuring out what went wrong for the Republican Party, and how they'll need to change their thinking to reflect the country's current demographics and remain competitive on a national level. That the GOP can't ever again rely on just the white vote is already a popular refrain. They can't keep alienating women with weird rape comments. They have to find some way to appeal to Latinos. And they surely have to rewrite their middle class agenda in such a way that it actually connects with middle class voters.
To each of those points I'll add one that I suspect actually encompasses them all (OK, maybe not the weird rape stuff): Republicans can never again concede all of the urban vote to the Democrats.
We already know the population trends here: After decades of declines, our cities are now growing faster than our suburbs. We're also well on our way to becoming a majority-minority nation, with our major metro areas serving as ground zero for the shift.
But all you really have to do to appreciate the role of the urban voter in 2012 is look at the sub-state-level maps of Obama's winning electorate. Since it's early still and votes are still being counted, I'll compare the county-by-county maps of both the Washington Post and The New York Times from this morning. Here's the Post's:
And the Times':
Even a county-level analysis will miss a decent level of detail, but the pattern is still pretty clear: Obama looks like he's won the popular vote by two or three percentage points on the strength of his performance in our densest urban areas. That lonesome blue square in the upper right hand corner of Texas is of course Dallas County. Northern Virginia's high-population urban enclave has narrowly carried the state for the president. It's not exactly hard to pick out the most populous county in Nevada, home to Las Vegas. And so on.
The math of assuming cities will go to Democrats and thus not bothering to craft a message aimed at the people who live there is just a losing game going forward for Republicans. And it's only going to get worse as urban populations increase and become more concentrated.