In my previous post, I noted that the distinction between a tax and a regulation was well understood by the American revolutionaries. The distinction had to do with the purpose of the law. A tax was a law that was designed to raise money to pay for government, and a regulation was designed to influence (or regulate) human actions. To be sure, taxes do influence behavior, and many regulations do raise revenue, but those features are incidental to their purpose. Hence the colonists thought it would be legal for Parliament to regulate trade by making foreign molasses more expensive in the colonies, but Parliament could not legally impose a duty on foreign molasses if the main purpose of that duty was to raise revenue.
Tories, according to the American definition of the term, claimed that this was a distinction without difference. From their perspective, all laws that raise revenue were equally legal, regardless of the purpose of the law. For their part, the American Whigs said that the difference between a tax to raise revenue and a duty to regulate trade was obvious and important. Their constitutionalism focused on ends as much as it focused on means. Because the government existed, in part, to secure property, it was unconstitutional for Parliament to tax the colonists without their consent.