So a plurality of McCain voters in that precinct are black (which actually isn't that odd, since blacks make up about 80% of the total population there)? I actually wonder in how many precincts nationwide were a plurality (or in some cases, a majority?) of McCain voters black.
Probably almost all precincts where virtually everyone is black.
In Georgia (varies by county in any state, obviously), the precincts will generally need to be at least 92% black and the white number will need to be less than half of the remainder. I actually made a map of this for GA this morning but it's on my other computer. Something like 135 precincts in the state; almost all of them in Atlanta. There were about 10 scattered elsewhere in the state (Columbus, Augusta, Macon, Albany, Savannah & Valdosta - no rural precincts fit the bill).
EDIT: Ugh, looks like I lost the map. I do have the tabulations, though.
97 Fulton (ATL)
39 Dekalb (ATL)
5 Chatham (Savannah)
5 Dougherty (Albany)
3 Richmond (Augusta)
1 Bibb (Macon)
1 Lowndes (Valdosta)
1 Muscogee (Columbus)
152 Georgia (Statewide)