Re: "Dawn Raid Manual"
If you want a retroactive law in the US, checkout the 1993 tax hike. Passed after president Clinton assumed office, it took effect 1/1. Of course, for some strange reason Her Royal Clinton just happened to have asked to be paid for some of her 1993 "work" for some law firm in 1992--a request that was granted.
Yes, our written constitution has a clause against that. Constitutions are only worth the people who enforce them.