Bellesiles is a good example for John's point about how those trying to change public policy with academic studies should release their raw data. Bellesiles had a huge influence in the gun-control movement with his bogus statistics, until the NRA and others called him on it.
One of the main points of the Bellesiles article is to attack the idea that there was a consensus about the meaning of the US Constitution and the Bill Of Rights when they were adopted. It is indeed a historical fact that there were sharp political battles over many issues, and a lot people did not even have any political influence. But there was a consensus about the meaning of most of it.
A law that was passed by one vote has the same validity as the one that was passed unanimously. To apply the law, it is often useful to look at what people meant by the law at the time the law was passed. It is usually not relevant to note that the law was controversial. Bellesiles seems to want to argue that the Constitution and Bill Of Rights should be taken less seriously because they were controversial. The argument is nonsense.
Bellesiles cites Posner as saying historians do not know history and are useless in offering guidance on public policy. Bellesiles is the proof.