Earlier quoted context omitted.
What would your proposed law say? Congress can't make a law that says that it can't make a SOPA-like law in the future (or, at least, it would be meaningless, since future legislation could repeal it).
There should be a way for the people to veto a law in a referendum, like in Switzerland. That way politicians would be more cautious passing laws which they know that the public probably won't like and probably will veto. The current US system only provides "checks and balances" between political parties, so when one party cracks up (meaning, gets bought by special interests and turns against the people) we only can…
We have to be very careful with this. Sometimes a very popular law is exactly what you don't want. There are vast areas where a law mandating the teaching of creationist superstition in science classes would be immensely popular while a law forbidding it would be very unpopular.