I don't believe in DNS censorship. It's one of the more futile versions of state control. Reading about the US/Mexican censorship of 1dmx.org it took me about 3 minutes of research to realize these were not my kind of people (they seem to be allied with the hard left PRD) and about half a second more to decide that their ideology didn't matter. An attack to hide a sight by taking down their DNS entry doesn't stink less because I don't like the people being attacked today. The targets will change soon enough.
The solution seems obvious enough, crawl the DNS tree from the roots and take snapshots to create a database of the DNS tree over time, similar to the way the Apple's Time Machine does for the contents of your desktop PC. The model is there for everybody to see at archive.org which keeps a handy time machine of much of the Internet. Setting up a distributed network of older DNS entries that can be queried by others in case of takedown would allow for cross jurisdictional barriers to be set up so that political censorship would have a much tougher time shutting up timely sites.