This is obviously not meant to be in any way comprehensive.
For the ancient analysis of regime types, including democracy
The natural rights basis of government
The analysis of the English constitution with an emphasis on separation of powers and checks and balances.
A polemic defending the revolutionary cause.
(if just a selection then perhaps 1, 10, 39, 51, 70, 78, and 84)
Early debates on the nature of presidential authority
On religious liberty
On the necessity of revering the Constitution in the face of the dangers of mob rule
Justification for the anti-slavery interpretation of the Constitution