I think the only region where Vandy comes close to the other 2 is the South, which has fewer people than any other region.
If you go by which states were part of the confederacy, the south is the most populous region. If you go by which states are clearly in the south , and by which states are clearly in the northeast , then the former still has several more million people, and is still either the most populous or second most populous region depending on whether you split the west up into the coast and the mountain region or combine them together.
 VA, WV, GA, NC, SC, AL, MI, AK
, LA, KY, TN
 CT, MI, MA, NH, NJ, NY, PA, RI, VT, DE
What?! The last time I checked, West Virginia (who cares?), Michigan (MI) and Alaska (AK) were not in the South. I guess you were trying to say Mississippi (MS) and Arkansas (AR).
Let's tabulate the electoral college votes in these regions. And I'm eliminating West Virginia from consideration. It is not in the South, nor has anyone in that whole state heard of any school other than Harvard or WVU (my mom is from West Virginia). I'm also adding Maine (ME) to the Northeast.
 VA, GA, NC, SC, AL, MS, AR, LA, KY, TN
13, 15, 15, 8, 9, 6, 6, 9, 8, 11 = 100
 CT, MI, MA, NH, NJ, NY, PA, RI, VT, DE, ME
7, 17, 12, 4, 15, 31, 21, 4, 3, 3, 4 = 121
So, you're wrong. Also, if we eliminate Michigan (MI) from the Northeast, it's still 104 which, last I checked, was more than 100 (albeit only barely).
Also you seriously need to brush up on your general knowledge / postal abbreviations.
Um, why the hell are you using electoral votes to compare population? Alabama has 3x as many electoral votes as Vermont while having almost 8x as many people...
Also, I wasn't counting Michigan in the Northeast, it's clearly in the Midwest. That MI is supposed to be Maine. Yeah, I got a couple of postal codes wrong, sue me.
Even if we eliminate WV from the South, the latter still has about a million more people. And that's a pretty narrow definition of the South. The US Census bureau classifies WV/MD/DC/DE as part of the south, which IMHO makes sense. Been to Maryland lately? It's culturally very similar to Virginia and has a similar agricultural heritage. Alternatively, you could take PA/WV/MD/DC/DE/VA and break it off into a Mid-Atlantic region that probably better reflects their modern (as opposed to historical) alignments. The south is still bigger under that measure.