[Redbob]

"After the Stamp Act was passed in 1765, Clarke objected to it, not out of concerns for the economic well-being of Lexington, but on constitutional grounds."

Not likely !
When the Stamp Act was passed, the Constitution was still 22 years in the future.

Or do the Brits have a Constitution that they've been hiding from us all these years?

[Mulder]

Not likely ! When the Stamp Act was passed, the Constitution was still 22 years in the future.

That wasn't referring to the US Constitution, but rather the Massachusetts charter and the Magna Carta.

The word constitution, as used by the author, refers to "the system of fundamental laws and principles that prescribes the nature, functions, and limits of a government or another institution"