Gillum pulled victory off by cruising in relatively small number of Florida’s counties.

He carried 18 of 67 counties.
Levine carried 4 counties, all in the extreme southwest Peninsula as well as coming in 2nd in Broward and Miami-Dade.

Graham carried the remaining 45 counties.

However most of Gillum’s counties were too small and inconsequential to make a difference. He won this election in three counties, Broward, Duval and Miami-Dade. The combined margins he ran up in those three counties put him over the top. He should thank Levine, who drained off a bunch of potential Graham votes here also.

He carried the following counties:

Alachua (Gainsville)
Broward (Fort Lauderdale) - He was helped here by Levine draining off 45,000 votes from Graham, Levine actually finished second here.
Clay (south suburbs of Jacksonville)
Duval (Jacksonville) Not surprisingly he crushed his opponents here.
Escambia (Pensacola) Surprisingly, he crushed his opponents here.
Gadsden (right next to Tallahassee and majority black, I believe he took a 3 to 1 ratio of votes here.)
Hamilton (on Interstate 75 right on the Georgia line)
Hendry (Small inland county in the south peninsula.)
Hillsborough (Tampa) He carried it by a modest margin.
Jefferson (right next to Tallahassee)
Leon (Tallahassee) His margin here was very modest, given he is the Mayor of Tallahassee.
Madison (right next to Jefferson)
Miami-Dade (He carried it by a 2 to 1 margin over Graham and Levine drained off 48,000 votes from Graham here, Levine finished second here.)
Okaloosa (Far west panhandle)
Orange (Orlando)
Palm Beach (West Palm Beach)
Santa Rosa (Far west panhandle)
St. Lucie (Fort Pierce)

Surprisingly, he finished 2nd in Pinellas (St. Petersburg), well behind Graham.