Devilstower has a post over at the Orange Satan that summarizes the Bush reign of incompetence in some of the key numbers...let's call it the "Shrub Delta". You should read the post for the detail but here are the high(low) lights;
Unemployment up 3%
Median Income down 2%
Stock Market down 37%
US Crude Oil Production down 13%
US Crude Oil Imports Up 13%
National Debt Up 86%
Of course, there are plenty of other numbers to track. Illegal signing statements. Violations of the Constitution. Americans and non-Americans killed in an unnecessary war. Idiots put in charge of stuff. Industry cronies put in charge of regulation of the same industry. American cities lost. Terrorist attacks on American cities. There are many more and feel free to add them to the comments.
