Out of spite, I just might flood these streets
This is a continuation of the previous lines. He’s saying let him commit a real crime by buying a kilo for Chief Keef and “flooding” the streets by dealing it out at a low price. Using “Chief Keef” plays on the rapper’s drug inspired name and Keef’s recent controversies. Jay may be a businessman, but he never left that life. He raps this line in a sound very similarly to Chief Keef.
Expanding on “flood these streets”: given the topic of government and politicians, a listener can infer government failure in Katrina “flood these streets.” It’s a play on the government flooding New Orleans' streets by not dealing with Katrina, versus Jay giving the government trouble by bringing in cocaine to metaphorically flood the streets.
To help improve the meaning of these lyrics, visit "Open Letter" by Jay Z Lyrics and leave a comment on the lyrics box