Megan McArdle makes a number of sensible claims about the non-danger of citizens legally carrying legal firearms at public political gatherings where the president appears. Jason Zengerle accuses her of being both “silly” and “offensive.” He writes:
This is very silly. Look, just on a basic level, the Secret Service's capacities aren't infinite: protecting the president is hard enough in normal circumstances; throw in the job of making sure gun-toting protestors don't have a sight line on the president, and the agents' jobs become that much more difficult. Even if the gun-toting protestors whose rights McArdle is defending pose no harm to Obama, keeping a constant eye on them takes up resources–resources the Secret Service might need to thwart people who do mean to do harm to the president.
No, this is very silly! (See what I did there?) The silliest thing is Zengerle's casual assumption that if the free and peaceful exercise of an enumerated constitutional right “takes up resources,” then the state may therefore limit it. I doubt he'd like to generalize this principle. Of course, the real issue is likely that Zengerle is not impressed with the idea of an individual right to bear arms. So he's untroubled by limiting it on the grounds that it might cost a little money or slightly affect the probability of harm to the president.
Maybe the scenario wouldn't seem so clear-cut to Zengerle if it is redescribed to involve a right he cares about. So suppose that the act of visibly carrying a firearm is intended as an act of political expression asserting the legitimacy of the right to do so and challenging social norms that stigmatize and stifle the exercise of this legitimate right. I take it that this was in fact the intention of the “Tree of Liberty” dude. Or maybe it's no problem to limit disagreeable political expression as long as allowing it would impose an extra burden on the Secret Service?
Here's another (sure-to-be-unpopular) thought. Zengerle also seems to assume that efforts to protect the safety of the president do not already consume too many resources. The significance of the presidential role no doubt merits an uptick in the usual amount taxpayers ought to be willing to fork over to preserve each of a 48 year old's expected remaining quality-adjusted life years. But there are limits. In a recent provocatively rational paper, Swiss economist Bruno Frey, acting as a sort of one-man politician death panel, argues that:
[P]oliticians are overprotected. The costs of political assassination differ systematically depending on whether a private or a public point of view is taken. A politician attributes a very high (if not infinite) cost to his or her survival. The social cost of political assassination is much smaller as politicians are replaceable. Conversely, the private cost of the security measures is low for politicians, its bulk – including time loss and inconvenience – is imposed on taxpayers and the general public. The extent of overprotection is larger in dictatorial than in democratic countries.
The challenge that Frey poses to Zengerle is this: Even if it could be shown that citizens legally open-carrying firearms significantly increase the probability of an assassination attempt (I am skeptical), it might not be worth the cost to add resources to increase presidential protection. Indeed, Frey finds that politicians are already overprotected. So the presence of citizens with guns may do nothing more than slightly reduce the extent of overprotection.
Since Zengerle found “offensive” McArdle's claim that few anti-gun types are willing to reveal their true estimate of the probability (i.e., to bet) that “one of these firearms is soon going to be discharged at someone,” I assume he'll find Frey's calculus appalling. But if we can apply cost-benefit analysis to taxpayer-funded end-of-life medical treatment, we can apply it just as well to taxpayer-funded bodyguards and bullet-proof limos.
Anyway, I'm pretty sure this attempt to be rational on the subject of privately-owned guns near the president is in vain. If we make a Venn diagram of the set of people for whom guns are bewitched totems of death and the set of people for whom the president is a majestic, semi-divine symbol of national identity, I think we'll see a fat overlap.