Density Matters

Here's a map of the counties holding 50% of  U.S. population:

And the kicker is, this doesn't even tell the whole story.  Montgomery County, Ohio is highlighted, and at least half of the county is fairly sparsely populated.  For another example, look at southern California.  This is a map from 2000, but look at how much empty area is shown in the area in blue on the map up above (probably 75 percent of the largest county in the United States, and even a good amount of area in Los Angeles County, the most populous in the U.S.):

Honestly, nobody in rural areas can really understand what population density means to life in the United States.  We're all raised up on the Bush-Gore county-by-county election results, but yes, there are a fuckload of empty areas in the U.S., and if you highlighted their voting preferences based on geography, they will look pretty Goddamned dominant.  That just isn't the case.  And that is why the Electoral College and gerrymandering allow the Republican party to be a national party.  That may not last (thank God), but it really is impressive visually.