Okay, Jason, here’s more (incidentally, we’re dicussing whether they influence the Constitution, not whether they were a democracy vs. oligarchy): In addition to each of these innovations which are imitated in the Constitution, it is also well known that the Founding Fathers made occasional political trips into Six Nations territory to observe and participate. James Madison, William Livingston, John Taylor, Benjamin Franklin, and others all arranged visits with chiefs, and Thomas Jefferson took notes to record unique facets of Haudenosaunee Government. Several of the authors attended decision-making councils with tribal members and were openly attracted to their system of representational governance. These same men later invited delegates from the Iroquois league to advise them on American politics as well; Franklin later marveled that “It would be a strange thing…if six nations of ignorant savages should be capable of forming such a union and be able to execute it in such a manner that it has subsisted for ages and appears indissoluble, and yet that a like union should be impractical for ten or a dozen English colonies.”
Professor Donald Grinde of the University of California at Riverside observed,
People have accepted the fact the Iroquois were at the Continental Congress on the eve of the Declaration…and they’re having to deal with the fact that John Adams was advocating the study of Indian Governments, and that Adams observed that others among the founding fathers were advancing Indian ideas on the eve of the Constitutional Convention. But people have been led kicking and screaming into these realizations…It’s difficult to entertain the idea that the founding fathers were relating to, talking about, and evaluating the ideas of non-white peoples…it goes against the conventional wisdom of our society." (REF: Grinde, quoted in Mander, which I cited below)