After posting a map of national championship winners from the past 50 years and how many of them are in or near the Big Three talent producing states of Florida, California, and Texas, commenters mentioned that the 85-scholarship limit makes being near a talent pool even more important. After all, fewer players on a team means there are fewer extra chances if some players don't pan out.
The 85-scholarship limit went into effect in 1994. If you want to see the numbers on the span of '94 to the present, I put them in this comment on the original map post. In short, the rate of national title winners coming from inside or states that border the Big Three was about 11 percentage points higher between 1994-2014 than during 1965-93.
If you give the 85-scholarship limit four seasons to fully work its way into effect, then you're talking about the BCS/CFP era of 1998-present. It's not that long comparatively, so I decided to look at national championship game participants rather than just the champions. It doubles the data set and still includes some of the nation's best teams from each of those years.
Here is the map that comes from this:
Map adapted from here.
In all, 26 of the 34 teams (76.5%) to play in national championship games were either from the Big Three or states that border them. Toss in the ones from or bordering the fourth big area, Ohio and Pennsylvania, and it's 31 of 34 (91.2%).
Notre Dame from 2012 is a pretty great example of this. It's always been a national recruiter, but where does it look? That Irish team had eight players from Indiana, but players hailing from Florida (12), Ohio (11), and California (10) outnumber the home state guys. Sure, bordering Ohio made a difference for ND, but it also mined Florida and California at similar rates. Those states are where you want to be.
This past season's semifinal losers were from Alabama and Florida. The other two teams that felt they had a case to be made for making the top four were from Texas. Those aren't accidents. It's not impossible to compete for titles without being in or right next to one of the four talent centers, but you probably have to pull a decent number of players from those centers to pull it off. Good luck to anyone not from those places.