Tim Blair disputes Charles Johnson’s estimate of the size of the September 12 rally. Johnson wrote:
Here’s the Washington DC Metrorail service information for Saturday, September 12, 2009:
September 12, 2009: Metrorail: 437,624
Comparable Metrorail Ridership 1 Year Ago: 362,773
The difference between these two figures is — 74,851.
Oddly enough, this almost exactly matches the unofficial estimate given by a Washington DC Fire Department spokesman, who estimated the crowd at 60,000 to 70,000 people.
comparing September 12, 2008, to September 12, 2009, won’t yield reliable information – because the first date fell on a working day (Friday), while the second was a Saturday.
Which is is why the comparison was with Saturday September 13, 2008.
Blair quotes Mark Kelly of the Heritage Foundation:
For a fair comparison, we looked at the Saturday after Labor Day in 2008, which is when September 12 fell in 2009. On September 12, 2009, 437,624 rode metro rail. By comparison, on the Saturday after Labor Day in 2008, 202,528 rode. The difference is 235,096.
Kelly is comparing September 12, 2009 with September 6, 2009 instead of September 13. Why does this make such a difference?
Let’s look at all the figures for Saturdays in September:
The numbers range from about 300,000 to 350,000, but there are two outliers: September 6, 2008 with 202,528 and September 24, 2005 with 464,398. What happened on those two days?
On September 6, 2008, [Tropical Storm Hanna hit Washington DC](http://www.washingtonpost.com/wp-dyn/content/article/2008/09/06/AR2008090603047.html):
>The first tropical storm to hit the Washington area this season left the region windblown and thoroughly soaked yesterday, causing one fatal car accident, flooding dozens of roads and turning quiet suburban creeks into fast-rising, muddy rivers.
Clearly it is wrong for Blair and Kelly to use the day Hanna hit DC for comparison.
And September 24, 2005 was [the day of an anti-war march](http://www.washingtonpost.com/wp-dyn/content/article/2005/09/24/AR2005092401701.html):
>D.C. Police Chief Charles H. Ramsey, who walked the march route, said the protesters achieved the goal of 100,000 and probably exceeded it. Asked whether at least 150,000 showed up, the chief said, “That’s as good a guess as any.
Based on the increase in ridership over a normal September Saturday, the September 12 march was 80% of the size of the September 24, 2005 one, suggesting there were at least 80,000 people and possible as many as 120,000.
And what did Blair say about the September 24 anti-war march? [“Numbers seem a little inflated.”](http://timblair.net/ee/index.php/weblog/cindys_people/). To support this he linked to Charles Johnson, whose arguments that he numbers were inflated were somehow much more persuasive to Blair in 2005 than they are now.