In the second quarter, Clinton received donations from about 5,300 ZIP codes. In the third quarter, that increased to 6,300.
That second quarter, when Clinton wrung a lot of money out of a lot of people, she pulled in a lot of money from Manhattan's wealthiest ZIP codes. In those ZIPs, roughly 10021 through 10028, Clinton raised $2 million from individuals in the second quarter. In the third quarter, she raised $725,000 -- a $1.3 million drop. (The densest area of circles below is Manhattan; you can also see the outline of Long Island to New York City's east.)
Notice how centralized her donations were in the second quarter compared to Sanders's. He got a lot more contributions from outlying ZIP codes.
This is what you'd expect to see from a candidate who got a lot of donors to max out early. Those areas subsequently have fewer donors to hit up.
But you might also have noticed how much better Sanders is doing in the lucrative New York market. Across the country, Sanders dramatically expanded the number of places from which he generated contributions, more than doubling the number of ZIP codes from which he got money from 3,400 to 8,400.
Sanders also saw an increase in how much he raised, versus the decrease Clinton experienced. We return to this chart that we published earlier this month.
Sanders has a lot more people now to whom he can go back for more money.