Rep. Eshoo: 'We will do whatever is necessary' to enact net neutrality

Ultimately, that means the FCC must re-classify broadband as a telecommunications service if it wishes to resume regulating it -- a process that is likely to be riddled with court challenges from Internet companies like Comcast, AT&T and Verizon. Alternatively, Congress could more explicitly define the agency's broadband powers through new legislation, though that route too seems politically perilous.

Still, Eshoo on Tuesday described that ruling as a "repudiation of the previous FCC's legal practices, rather than a delineation of broadband authority."

Comcast rightfully won the case because the FCC had not initiated a clear rule-making practice before it sanctioned the company in 2007, she wrote, leaving the court "no choice but to overrule the FCC."

But that outcome does not mean the agency is otherwise powerless to regulate broadband, the congresswoman emphasized. Rather, she said the FCC could use "current law to provide access to all Internet sites and content on an equal, neutral basis" -- a hint at the re-classification approach FCC commisioners are already considering.

"The court's ruling will not undermine our efforts to upgrade and modernize the rules governing these core industries," she said. "This narrow decision did not say that the FCC lacks authority to oversee the Internet or even dictate a method for doing so, because the law clearly permits the FCC to regulate broadband."