There’s no Obamacare for the internet. But there could be a public option.

Because Sen. Ted Cruz loves political journalists and wants them to be happy and get traffic, he responded to President Obama’s big net neutrality announcement by tweeting that network neutrality is like Obamacare for the internet:

It isn’t at all clear what “Obamacare for the Internet” would mean even if someone did want to try it. Would there be an individual mandate requiring everyone to buy internet? Would there be government subsidies for people who don’t have enough internet? Would the government create payment schemes wherein internet providers got paid based on the quality of the internet that people consumed rather than the quantity of it?

(Related: Obama’s big net neutrality announcement, explained.)

But if Obamacare for the internet isn’t a particularly meaningful concept, a public option for the internet is. Susan Crawford, the John A. Reilly Visiting Professor in Intellectual Property at the Harvard Law School, explained the idea to me in an interview:

Ezra: Why do we need a public option for internet access?

Susan: We need a public option for internet access because internet access is just like electricity or a road grid. This is something that the private market doesn’t provide left to its own devices. What they’ll do is systematically provide extraordinarily expensive services for the richest people in America, leave out a huge percentage of the population and, in general, try to make their own profits at the expense of social good.

When it comes to fiber penetration — that’s the world class kind of network we should have — we’re behind Sweden, Estonia, Korea, Hong Kong, Japan. A whole host of other developed countries. We should be looking the rest of the world in the rearview mirror. Instead, for more than 77% of Americans, their only choice for a high capacity connection is their local cable monopoly. So just as we have a postal service that’s a public option for communications in the form of mail, we also need public options in every city for very high-capacity, very high-speed fiber internet access. That way we’ll make sure and we can compete with every other nation in the 21st century.

The idea, basically, is that internet access tends to devolve into “natural monopolies” that limit competition and innovation in profitable, urban areas and lead to terrible service in rural areas.

“It really makes sense to have one wire going to your house,” Crawford continues. “The problem is we’ve gotten stuck with the wrong wire. We’ve got a cable wire and it should be fiber and it should be then shared by lots of competitors. That’s what drives prices down. If you hand the one company the ability to control that market they’ll just reap their rewards and price discriminate and make lots of profits.”

And so the government should step into to provide a public alternative based on high-speed fiber infrastructure. There’s much more in our interview: