Color me perplexed.

The same people who railed so strongly against Citizens United and lament the alleged corrupting influence of corporate money in politics now express concern about last week’s Supreme Court ruling prohibiting unions from levying special assessments against non-members in a closed shop, when the levy is intended for political agitation.

If you cut through the rhetorical crap, the message seems to be: Corporate speech bad, activist/labor speech good. Nice gig, if you can get it.

You see this tendency most audaciously expressed with some of the defenses offered of late in support of Mayor Bloomberg’s fatwa against sugary beverages. One friend of mine, who used to be a libertarian before he drank deeply from the Obama Kool-Aid (now there’s a sugary, nutrition-free drink I’d favor banning!), told me that bans are justified in part because corporations market sugary drinks to the masses, and the masses therefore are sufficiently influenced that they sip their way into an obesity that translates into socialized long-term avoidable health care costs. Only the power of the state, wielded by the vanguard of health commissars to ban large-size sugary drinks, can turn the tide against the wave of obesity set to roll across America like muffin tops on the first warm day of spring.

When I ask whether individuals should accept responsibility for what they consume, the response is: Well, corporate marketing influences people, so deploying state power to regulate what they’re marketing is permissible.

My response: So what? I’m exposed to hundreds of marketing messages each day. I saw like a dozen tampon ads on TV yesterday but that doesn’t mean I’ve developed a subliminal compulsion to purchase feminine hygiene products.

Marketing has two primary purposes — to make someone aware of a new product or service and to influence a person’s decision about which product or service a person should partake when shopping in a specific market. Hence, the goal of a Ford ad is to get you to buy a Ford when you’re in the market for a new car — not to force you to join the car-buying market.

Don’t be fooled: The Bloomberg ban and anti-corporate-speech agitation stem from the same root — the belief that corporations have an agenda that almost universally is inconsistent with the public good, and that citizens are usually incapable (to their ultimate detriment) of escaping the marketing messages of these corporations.

In short, it’s a conspiracy theory. Evil billionaires deploy “advertising” and helpless citizens are compelled to obey, thus fattening the pockets of corporate hegemons while leading to environmental despoilation, obesity, false consciousness and whatnot that the rest of society will have to pay for. Only the power of the regulatory state can protect the people from utter ruination while protecting society from the harmful externalities these fatcats would force society to bear.

Of course, there are two chief problems with this schema, apart with the slighlty snarky way I’ve presented it.

First, to the extent that corporations are legal entities, it’s not clear why their speech should be less protected than that of other organized groups. Corporations are associations of citizens who band together for a common purpose — e.g., profit. They’re often beholden to shareholders who prefer that the corporation focus on profit and not on social engineering. In this sense, corporations are fundamentally no different from other associations, including labor unions and political parties and non-profit interest groups. They are aggregations of people joined together for a common purpose. That one’s First Amendment rights should be curtailed on account of that purpose (provided, of course, the purpose is legal) seems odd. Any restriction on corporate speech, for example, should mirror restrictions on union speech or the speech patterns of various NGOs and non-profit entities.

Thus, just like corporations can’t withhold money from employee paychecks to pay for lobbyists, so also should union members be free from having dues deducted without their consent to engage in political lobbying. What’s good for the goose is good for the gander.

Second, the specific claims against profit-seeking corporations rely on a curious thesis — that citizens are largely powerless to resist marketing. Although it’s undoubtedly clear that marketing influences behavior, marketing doesn’t determine behavior. If you’re thirsty and want a sugary beverage, and are in the mood for a 12-oz. serving, you’re not going buy a 44-oz. Ultra Gulp simply because you saw an ad for it. There’s no strong correlation between marketing and people engaging in self-defeating behavior. If you want 12 oz. of a drink, you’ll buy 12 oz. of a drink. The claim that corporations make it cheaper to buy in bulk — say, 44 oz. for $2 and 12 oz. for $1 — and therefore people will buy more than they want (at a higher total sale price) because they’re programmed to be bargain shoppers on a unit basis, strikes me as odd. Price sensitivity is a decision point for some people, but if you’re not price sensitive then bulk rates aren’t going to play into the analysis. If you are price sensitive, then this was already a factor that’s not related to a specific marketing initiative. Cart, horse.

Put slightly differently: Anti-corporate activists mistake the weak correlation between marketing and purchasing and assume that this correlation necessarily implies causation; this causative effect, in turn, needs to be regulated when people make market choices that these activists argue aren’t in the people’s best long-term interest.

My thought is this: Yes, some people are more sensitive to marketing messages than others, but the decision to engage in one behavior rather than another depends on a complex interplay of causes and effects — of which, corporate marketing messages necessarily play a very small part. If you’re going to drink enough Coke or Pepsi to become morbidly obese, then the determinative factor is likely a genetic predisposition to obesity or direct environmental factors and not TV commercials. To pick one very small and weak correlative factor and decide that it requires First Amendment restrictions seems like bringing a bazooka to a fly-fishing contest.

But even if we do decide that people are mind-numbed robots primed to obey every marketing message they receive even when it’s not advantageous to their survival, then whatever restrictions we place on corporate free speech must then be reflected in similar restrictions on the “corporate” speech of other corporate entities like labor unions, do-gooder non-profits and the like. Our system of laws requires equal treatment for equal conditions, and privileging the speech of non-profits over for-profits just isn’t supported by a content-analysis claim under the First Amendment.

The moral of the story: Attempts to regulate sugary drinks or corporate speech all spring from the theory that the average citizen isn’t capable of responding responsibly to marketing messages, therefore those messages must be regulated by benevolent overseers in government.

It’s for your own good. You moron.