A fierce fight is unfolding over the turnout at Saturday's demonstrations in Washington--undoubtedly one of the largest anti-Obama mobilizations since he took office--even as official estimates from the fire department have pegged the number at tens of thousands. This is no small number, so why the debate?  Crowd numbers are notoriously tough to measure, and obviously lend weight to political protest.

In this case, the rumor spread that 2 million people had turned out onto the mall, but the supposed source of the estimate, ABC, disowned the figure and argued that it stood at 60 to 70 thousand. Many on the left began to crow and brush away the protest, as some on the right did when Obama's inauguration drew 1.8 million people, far fewer than the 4 million that some expected. In measuring the importance of political demonstrations, is size all that matters?

• Overstating the Numbers Can Blow Up in Your Face, writes Nate Silver at FiveThirtyEight. After Michelle Malking admitted the figure of 2 million was exaggerated, Silver says that opponents are right to tease the relative smalness of the real turnout. "If you don't want to be discredited, then don't, as Kibbe did, tell a ridiculous (and easily disprovable) lie."

• Never Trust Event Organizers for Numbers, writes Joe Gandelman at The Moderate Voice. "Many times news gatherers will listen to estimates from event organizers but also talk with police and other officials because sometimes event organizers have it in their interest to inflate the numbers. Or they unconsciously fall into wishful thinking. The best bet is often to go with the police estimate."

• A Huge Crowd Is a Huge Crowd, writes Matt Welch at the New York Post. Welch thinks official estimates are too low, pegging turnout from his on the street view at 100,000. But he particularly takes the left to task for trying to brush away a massive populist outcry. "How do you marginalize a significant protest against a politician or policy you sup port? Lowball the numbers, then dismiss participants as deranged and possibly dangerous kooks. In the case of Saturday's massive 9/12 protest in Washington, done and done."

• On the Ground, Marches Always Feel Huge, writes David Weigel at the Washington Independent. "This dispute won't end soon, as any veterans of anti-war protests could tell conservatives; it's tough to get accurate crowd counts and tough to believe that something that felt massive was not, in fact, historically large. This was the largest march on Washington by conservatives in anyone's memory."

• Don't Ask 'How Many' Came, Ask 'Why?' suggests James Joyner at Outside the Beltway. "Suffice it to say: A whole lot of people showed up. Michelle Malkin has crowd photos and there's no refuting that the turnout was simply massive. What's more interesting to me is not how many but Why?" Joyner notes that liberal critiques of the protest--that attendees had incoherent motives--is missing the point. "People who show up to protest are usually motivated by emotion rather than cold logic. They're simply angry at the direction they think they're country's going and want to vent their frustrations and show that they're not alone."

Want to add to this story? Let us know in comments or send an email to the author at bcarlson at theatlantic dot com. You can share ideas for stories on the Open Wire.