This post has been updated. See correction at the bottom of the page.
To some Bernie Sanders supporters, the Democratic presidential race must seem close. Their candidate, after all, has essentially split victories with Hillary Clinton in the more than 30 election primaries and caucuses since the process began in February — including several in a row recently.
Clinton, their thinking goes, may have a lead in pledged delegates for the nomination, but her sizable and (for now) critical lead among party leaders known as “superdelegates” could crumble if the Vermont senator continues winning.
Anything’s possible. But Clinton has already secured many, many more votes than the Vermont senator and, party rules and delegate grappling aside, is absolutely dominating the race in terms of raw support. This trend is likely to continue with large, Clinton-friendly states coming up, and it could undercut Sanders supporters’ “will of the voters” hypothesis going forward.
Clinton has won roughly 9.4 million votes, compared to Sanders’ 7 million, according to returns from U.S. states. Along the way she’s posted huge victories. Her margin in Florida alone (530,000 votes) is about the same as Sanders’ margin in his victories combined.
Here are a few quick sketches (see correction below) that help illustrate this fact. First, let’s look at their states on a scatter plot to explore not just the number of victories for each candidate but the size of their respective states — and the relative victory margins:

Here’s a similar view in the form of a bubble chart (or, Alastair Dant would say, “BALLS!”):

And, finally, two maps. Again they show the large margins — and geographic differences — evident Clinton’s victories:

UPDATE: A Twitter user suggested I look at the data with time in mind. Not sure it proves his point, but here’s another sketch:

The charts were made with Tableau Public, a useful tool for sketching with data. You can see interactive versions of the charts here: Scatter | Bubbles | Maps | Time.
(Correction: Some caucus states — Washington, Nevada, Maine and Wyoming — reported candidates’ proportional number of delegates selected to state conventions, not actual votes. The charts below now reflect margin estimates extrapolated from the total Democratic caucus participation by delegate share, like this. The charts were updated to reflect these estimates. The central idea of the post, and the overall popular vote margin difference between the candidates, remains virtually unchanged, however.)