Just how big was the September 12 protest march? It’s hard to say. The estimate of “tens of thousands” is pretty conservative, given what I saw when I was down on the Hill that day. Talk of “millions,” on the other hand, seems quite outlandish.
One objective measure that could offer some perspective is the Metro ridership number for Saturday. Although they are often sparing with other information (such as their employees’ compensation), Metro posts the figures for daily rail riders (and for bus riders, with a month delay).
For September 12, there were 437,624 riders. That doesn’t come close to Inauguration Day’s 1.12 million riders, or even the 631,000 riders for July 4. But it still stacks up fairly well compared to this summer’s Saturdays, which average out at about 253,000.
Based on that alone, it seems like an estimate of something above 100,000 is probably safe, especially considering that not everyone would have gone by Metro.
