The New York Times followed up their fascinating baseball fandom map with an NBA version, and it's equally fascinating. You've got to click around and do some zooming and look at their selected close-ups for the real learning, but the upshot is evident from far away:
That's a lot of purple. Even after a 27-55 season, the Lakers are still the default team in regions without a natural local partisanship pretty much everywhere but the Southeast (Heat). That comes with the caveat that this map is based not on poll data but Facebook "likes," so take it for what it's worth. It's fun.