First, the basics. The records run from April 1, 2015 to February 1, 2016 and include donations from individuals. PAC and political party donations are not included. FULL DISCLOSURE: I donated a whopping $3 to Sanders in February. Unfortunately, I'm outside the time range so I don't get to drag his average down further.
The first observation is that Bernie out-fundraises Clinton because he has triple the donors giving one-third as much per contribution.
The maximum donation allowed is $2700, so I split the donations into small ($100 or less) and maximum ($2700) categories to see how the two candidates do at the ends of the spectrum:
Max donations account for more than half of Clinton's total contributions, while for Sanders they account for about 2.5%.
Here is each candidate's cumulative donations over time:
As you can see, Sanders overtook Clinton on January 25 after trailing since the beginning of the season. Clinton's lead was sustained by a big surge in June 2015. I checked to see what was going on on June 20, the end of the increase, and found that Clinton hosted a $2700/ticket fundraiser called "Conversation with Hillary" on that date at the Madison Park home of a donor. Tickets went on sale in early June. Since money is speech, I wonder if Clinton was able to get a word in edgewise.
Lastly, here is a map of contributions by zip code. The pie chart on each zip splits the donations into Clinton and Sanders slices. Use the tool to the right of the map to filter the contributions into >$100 and <$100 categories:
The difference between the two candidates' shares of small donations and large donations is striking. Clinton receives a majority of large donations in most zip codes, while Bernie takes an overwhelming majority of small donations in almost every zip code.
The numbers from Oregon tell a fairly similar story. The summary:
As in Washington, Sanders has more than triple the number of contributors and less than 1/3 the average donation size. Here's Small vs. Large Contributions:
Again, Clinton draws more than half of her money from maximum contributors; for Sanders, it's 2%.
The cumulative contributions tell the same story, down to the Clinton surge ahead of an expensive fundraiser visit. Tickets for the August 5, 2015 event went on sale July 10.
The map tells a similar story to Washington, with an even greater polarization between neighborhoods, and small and large donations. In Portland's Southwest Hills, for instance, Clinton takes 89% of contributions over $100, while Sanders takes 82% of contributions under $100. In my own neighborhood, NE Portland, 98.5% of small donations go to Bernie:
Looking at the map, I noticed that in the Portland area, the Willamette River seems to be a dividing line between Clinton and Sanders fundraising majorities. Sure enough:
There are a lot of conclusions you could draw from this stuff, but to me the basic takeaway is that, at least in the NW, a larger group of individuals of more modest means see Sanders as the candidate representing their interests, while individuals with thousands of dollars of expendable income see Clinton as representing theirs.