Maybe the authors of the Federalist Papers were liars. Maybe they were just engaged in political propaganda in order to shove through the Constitution. In secret, perhaps, they were plotting a Leviathan state with a president who can do all that the Bush administration claims he can, which pretty much amounts to whatever Bush wants to do.
If that was the case, they knew better than to advertise it. The Constitution would never have passed. Fear of a powerful president was one of the main reasons that people were fearful of abandoning the Articles of Confederation, which had no executive to speak of.