First, I'm not pushing any particular political agenda.  There's considerable debate around this chart, so I don't want to start any arguments.  The debate isn't around the validity of the data, but about how it's being presented.  The information is freely available from the U.S. Department of the Treasury and the Bureau of the Public Debt.

Second, I like that this chart takes a simple bar chart and adds a few more layers of information.  At its root, this is a timeline of the increase in the national debt based on the federal budget by year.  Then layered on top of that are the presidents in office that year, some color coding, the political party controlling the White House and highlights for record years.

Third, just to share the reasons for the debate.  This is a great example of data being visualized with a specific agenda in mind.  Obviously, this is a chart framed to make Republicans look bad, and Democrats look good.  The debate centers around a few issues like programs started by one President will carry into the term of another President and more importantly that the political party controlling Congress actually has more impact on the federal budget than the President does.