On Saturday in Boston, 20,000 people showed up to hear Bernie Sanders speak. It's the latest huge crowd Sanders has drawn in his long-shot bid for the Democratic presidential nomination. That means something — or nothing — depending on which member of the Fix team you are talking to. Chris has written repeatedly that the size of Bernie's crowds are an indicator of an organic energy for him that every politician craves. Philip has been skeptical, noting that while 20,000 people seems like a lot, it's a pittance when it comes to the overall number of votes a candidate needs to actually win.

We decided to settle this the only way journalists know how: trial by combat. But there were some legal concerns raised about going that route so, instead, we decided to have an online argument in this blog space. Pretty similar stakes. Below is our conversation.

Chris: I'm glad we're doing this since you usually just troll me on Twitter when you disagree. [BOOM. Point, Cillizza.]

I tend to think your analogy of crowd size to yard signs is overly simplistic. Putting a sign in your yard takes roughly zero effort. Wading through a big city to get to a crowded event on a Saturday afternoon takes way more. I know that I don't go to stuff all the time because I (a) can watch it on TV, (b) dread the crowds or (c) am very lazy. So, when 20,000  or even 5,000  people show up at a Sanders event, it's hard for me to totally dismiss it. Especially when  and this is the case in Boston  it's double the largest crowd ever for a presidential primary event.

I'm not saying  and I put this in the piece I wrote  that 20,000 people in Boston equals President Bernie Sanders. But, I have a hard time believing it means nothing at all. Are you a nihilist, Philip?

Philip: Hello. Hello, readers.

First of all, let's back up a little bit. You've written about Sanders's crowds a few times, which I think was part of the reason that I looked at it in August. At that point, I argued that the crowd sizes didn't mean much  a position I still hold.

Do they mean nothing, as is suggested by the little straw figurine of me you keep on your desk? No, of course they don't mean nothing. They just don't mean much.

Please note that I'm not the one who made the lawn-sign analogy. Lawn signs are indeed utterly useless and a massive waste of money. They're good for candidate egos and for cheering/worrying the politically unsophisticated, but that's about it. Crowd sizes are over-interpreted in the way lawn signs are, but they mean a little more  after all, people can vote and lawn signs can't. And standing in a room hearing Bernie Sanders holler at them for an hour or so will probably convince a few people to vote. So there's obvious value in having people attend rallies.

The problem with suggesting that crowd size is a valuable metric for gauging enthusiasm is that crowd sizes are rarely comparable to one another. You compare Sanders's turnout to President Obama's turnout for a rally in the 2008 cycle, as though this is an apples-to-apples comparison. "TWICE AS MANY PEOPLE CAME TO SEE BERNIE SANDERS ON A CHILLY OCTOBER DAY IN 2015," you yelled  sort of glossing over the fact that Obama's rally was outside, in Boston, at night, on a day that dropped below 60 degrees. There are any number of other factors, too. Sanders is putting an emphasis on the value of crowd size, the sort of thing that might inspire more people to attend. Obama was also not a senator from an adjoining state. And so on.

Oh, also: Obama lost the Massachusetts primary. By a wide margin. Obama would have needed 19 more rallies of 10,000 people to show up and vote for him that day in order to beat Clinton. But of course we have no way of knowing if the people at Obama's rally  or Sanders's  were actually registered voters in Massachusetts.

Chris: Well, I am glad we got that whole can-lawn-signs-vote question cleared up. If we accomplish nothing else today, we've done society a great service.

And, let's say that you are right that comparing crowd sizes between elections, venues and day/night is too apples-to-oranges to make sense. So, take away the "double the crowd that Obama drew" factoid  though I still contend that is sort of amazing given what a political phenomenon Obama was at the time. I still think 20,000 people showing up to a political event  even if it was held at a day spa where you could get a free massage and they had those awesome heated tile floors  is notable.

This is Bernie Sanders, avowed socialist. He's running against supposed juggernaut Hillary Clinton, the biggest non-incumbent front-runner in the history of major-party nominations. How in the hell is he getting 20,000 people to events?

One other point: The crowds don't happen in a vacuum. Sanders just announced that he raised $26 million over the past three months and now has over 1.3 million donations to his campaign. Most amazing is that he held just seven  seven — fundraisers to collect $26 million. Clinton held 58 events to raise just $2 million more.

Crowds plus lots (and lots) of small-dollar donors equals a campaign movement.

Prove me wrong.

Philip: Ah, yes. Moving the goalposts, the last refuge of the scoundrel.

Crowds don't happen in a vacuum, which is true, because the crowds would suffocate. RIP crowds. But we're here to discuss whether crowds count, per your insistence, not whether crowds-plus-lots-of-money counts. Essentially, you're conceding the point by noting that crowds alone don't mean anything! With which I would agree.

Or, to put it in the context of the generic pop culture references you like so much, I feel pretty confident that I could sell you an anti-tiger rock, given that you appear not to be terribly insistent on any link between claim and outcome.

I'll also note that the reason small-dollar donors do matter emphasizes why crowds don't. Having lots of small-dollar donors means that there are a lot of people to whom Sanders can go back for more money. There is decipherable meaning in small-dollar donors that doesn't exist in random crowds of people.

Feel free to have the last word. You've got a lot of cleaning up to do.

Chris: Good thing I am an excellent cleaner-upper! (Years of practice.)

To make your anti-crowd argument work, you have to assume that people come to the Sanders rally, applaud some, then leave  never to be approached by a staffer for the senator or contacted in any way again. Of course, that's not at all what happens.

Every person who goes to a Sanders rally  or at least the vast majority of them  are asked to give their e-mail address, home address and, I am fairly certain, what sort of level of volunteering they would be willing to do for his campaign.

So, yes, having lots of small-dollar donors is good for exactly the reason you noted: You can keep asking them for money. But getting lots and lots of people into your rallies is good for a similar reason: Once they're there, you can hit them up for all sorts of things from putting up a yard sign (!) to becoming a precinct captain in, say, New Hampshire. That sort of stuff can matter as much (or more) to the success of a campaign than money.

[wipes hands, mops brow, high-fives self]