What other region in the U.S. could become as densely populated as the northeast in our lifetimes?

[daf09]

It may seem unconventional but I would say the southeast or south central texas. The southeast a large area geographically and there are two "megalopolis'" that could rival the northeast. First the Piedmont region starting in Birmingham moving through Atlanta and Columbia then Charlotte and Raleigh. Atlanta and Charlotte are both top 20 metros and Raleigh is the fastest growing metro in the country. And just like the northeast all the cities are situated on the same stretch of highway. Supposedly the soil in this "line" of the cities was richer than the areas around it so the population and economy thrived. Some call it the black belt because the rich soil meant more blacks during slavery. Not to mention that there is sort of an unspoken migration going on right now, people from New York, Massachusetts, Pennsltvania and the Midwest and the rest of the northeast are migrating to the south in en masse. The other area in the southeast is coastal florida but I don't see the area rivaling the northeast because it was hit especially hard by the housing crisis and florida will probably be under water in 50-100 years. Which brings me to south central texas which already has two top 10 metros (Houston, Dallas) and three top 20 (Dallas, Houston, San Antonio) with one of the fastest growing cities (Austin). Like Florida much of Texas will possibly be underwater but unlike florida the economy is thriving so people keep coming, many from the northeast. The west coast is too large an area to all be consolidated like the northeast. I can see the Pacific Northwest (Including San Francisco) growing much much more if the tech industry continues to grow but I don't see Los Angeles ever being included because it's just too far away and the economy looks less promising. Like someone else said LA, San Dieogo and Tijuana are can already kind of rival the northeast but they are separated by a military base and a heavily guarded border.

[Trafalgar Law]

California easily, especially when you take the Far Northern part of it out. From Sacramento (the northernmost MAJOR city) to San Diego is more than likely going to become VERY competitive with either the Northeast (census defined) region in population or the Bos-Wash Corridor (straddles two regions) in population.

I don't ever see the Northeast growing faster than what it already has been growing by. Outside of New York and Washington DC, the other cities do not have the infrastructure to sustain growth of over 1 million a decade. In fact, even in their high growth heydays, that actually never even happened in the Northeast, aside from New York.

In California on the other hand you have Greater Los Angeles and the Greater Bay Area that are both poised to do at least 1 million this decade, they have the infrastructure necessary to grow by that much as both have done it before (for Los Angeles, numerous times). That's not including San Diego and Sacramento and the rest of California, all of which are growing much more so than anywhere in the census defined Northeast (aside from New York) and more so than the Bos-Wash corridor (aside from New York and Washington DC).

The population of California is not at this time all that close, it's closing in on around 40 million people. The Northeast is at 55 million and Bos-Wash is also around 50 million or so (but they constitute different geographies). The gap will certainly close but in my opinion only other area of the country that has a shot of matching this population in our lifetime.