This is a very naive analysis, Matt.
First off, it wasn't all "140 characters or less" and it wasn't all "shouting." Countless people worked hard to organize folks to actually call and write their representatives and senators. Real people made real phone calls with real explanations of why this is bad.
A huge part of the issue goes way beyond SOPA and PIPA. The issue is that what is supposed to be *our* government has become driven by bribes ^H^H^H^H^H campaign contributions. "We the people" just don't have any real say in how our government runs. Laws are bought and paid for by megacorporations with deep pockets.
This is a fantastic example of what happens when the megacorporations go too far. There was massive grassroots activity via public web sites, social media and word of mouth. It finally boiled up so furiously that the mainstream media (which is actually owned and run by many of the companies in favor of SOPA and PIPA) was forced to take notice and cover it. I've lost so much faith in our government that I have been pleasantly surprised by the reaction of the politicos. It's certainly not enough - it should be obvious to anyone who listens objectively that SOPA and PIPA are flawed, so they should've been dropped like a hot potato.
The logical next step is for the politicos to look to e.g. the National Science Foundation or other hard science & technology organizations for a realistic analysis and plan of action. Unfotunately, I don't see it happening. NSF doesn't pay off politicos to run with the people's agenda.