Internet companies have a lot of social power and a lot of mind share and general good will among the population. They were a huge part of stopping SOPA. They could fight hard against non-neutral ISPs in the same way, blacklisting and banning non-neutral ISPs, serving banners that explain e.g. Comcast is degrading service and destroying the free web, suggesting alternatives. It could cause enough pressure for ISPs to change or competition to emerge (people might take a slower service that can go on twitter and facebook and youtube vs. a faster one where many websites people use are blocked), or even possibly for politicians to change the law by passing a bill. Politicians use Wikipedia and google and twitter too. Especially twitter.

Unfortunately I don't see this happening: large tech companies benefit from this arrangement and so it takes moral courage to do the right thing here on behalf of the leaders of these companies. There's some of that but not enough -- maybe I'm just being a pessimist.

General grassroots political outcry to stop the actual law changing is possible, but very unlikely to matter in this case either, I think. Unfortunately while SOPA was a law passed by votes, cast by human beings who are accountable to someone and can be threatened by angry citizenry, this is a regulatory decision literally nobody who is not a senior vice president at Comcast voted for or wants -- Pai has no constituents, all the power and none of the responsibility. He can sell the Internet to his friends at Verizon and then undoubtedly receive their gratitude in the form of a cushy job and $400,000 speaking gigs.