The Federal Communications Commission enacted its net-neutrality order in late 2010. The regulations prohibit Internet service providers from slowing down or blocking against legitimate websites. Cellphone carriers are barred from blocking apps that compete with their own services.
In its lawsuit, Verizon claimed that it has a First Amendment right to decide what traffic to carry on its network just as a newspaper editor chooses what articles to publish.
The company said the net-neutrality rules "strip providers of control over which speech they transmit and how they transmit it, and they compel the carriage of others’ speech."
In their letter, the Democrats warned that overturning the net-neutrality rules could undermine the success of the Internet.
"This incredible economic success story is made possible by the fact that the Internet has always been an open platform where anyone with a good idea can connect to consumers across the globe and compete on a level playing field for their business," they wrote.
They pointed to a brief defense of the rules filed by former FCC Chairman Reed Hundt, former FCC Commissioner Michael Copps and other former government officials.
In that brief, the officials said Verizon's lawsuit fails to "state any valid or even seriously plausible constitutional claim."
They argued that Verizon is only carrying the speech of others and not expressing any message of its own.
"There is nothing inherently expressive about transmitting others’ data packets, at a subscriber’s direction, over the Internet," the officials wrote.
But Verizon's First Amendment claim has always been secondary to its central argument against the rules — that the FCC overstepped its legal authority.
"Verizon has been a longtime advocate for an open Internet, and is the only Internet Service Provider that voluntarily adopted such policies. Our filing makes clear that we remain concerned that the FCC’s sweeping assertion in this case exceeds its statutory authority and constitutional limits," a Verizon spokesman said in response to the Democrats' letter.