What is a “faction” and why does James Madison fear it? Why does Mercy Otis

What is a “faction” and why does James Madison fear it? 
Why does Mercy Otis Warren define the new US Constitution and its government as “aristocratic tyranny” bringing “uncontrouled despotism”? 
Both articles express problems and possibilities of American politics if their side loses. Identify a problem address in one of the articles that you see in modern America.
Lets assume that you do not know that the Constitution will pass and that its for of government will last over 200 years. If you were a voter in the late 1890s and read both of these arguments, would you vote to ratify the Constitution?