https://www.nytimes.com/interactive/2019/08/02/us/politics/2020-democratic-fundraising.html
While Mr. Sanders has a sprawling list of donors nationwide, geographic dominance does not necessarily translate into a cash advantage of the same magnitude. Just as population density differs in urban, suburban and rural areas, the number of people who donate to political campaigns also varies widely based on geography.
Ranking as the top Democrat for individual donors in a densely populated urban area is far different from leading the field in an area where few people are donating to campaigns.
For example, Ms. Warren has more donors in a single ZIP code in Brooklyn than any candidate has in the entire state of Mississippi. Mr. Buttigieg has more donors in a single ZIP code in Washington, D.C., than any candidate has in South Dakota.