Why not? You would have us believe that Northern newspaper editorials speak for the entire U.S.
In terms of voicing fears, they certainly speak for a lot of their readership, but this is a very different thing than stating what is or is not in fact the actual law.
The opinion of a newspaper on the facts of law is irrelevant. They may accurately represent a cross section of their readership, but they have no authority in matters of law, especially when actual elected officials (in this case the entire legislature of Virginia in the founding era.) disagree with what they claim.