Your sentiment has already been beaten to death in pretty much every collegiate Comparative Politics class in the USA. Of course, we can blame folks like Andrew Jackson, Abraham Lincoln, FDR, Bush/Cheney for expanding the powers of the presidency; but really the system in and of itself is flawed.
There is a school of thought in comparative politics called "American Exceptionalism" -- in this case, meaning that the U.S. Constitution is exceptional in that it only works in the US -- other places that have tried using the American model, with the strong executive; end up devolving into dictatorships. See Dahl, Robert Polyarchy .
Believe it or not, is it actually the 5th Republic French Constitution (the DeGaulle constitution) that has proven the most successful in bringing democracy to democratizing nations.
Reforms like proportional representation, abolishment of the electoral college, and institutions to do away with the two-party system have been long in coming to the American political system to keep it in line with the modern conception of democracy. Instead, it keeps slipping into this vaguely democratic polyarchy.