This brings to mind the government set up in The Moon is a Harsh Mistress: it takes 2/3rds to pass a law, but only 1/3rd to repeal it.

The thinking being if a law isn't good/useful enough to garner 2/3rd support, it shouldn't be law. And if a law is so bad that it can't even get more than 1/3rd the people to support it, it should no longer be a law.

Sadly, I don't think it'd work today. People are too divided, it's too easy to import the votes you need, and people are too lazy to understand a law beyond the headline or what the news tells them about it.