I do like the chart, but to leave out Bush's second term simply leaves the chart as an incomplete portion. I understand that you're referencing their first terms only, I would think including the data and shading the area a certain texture would have been more informative.
The mention of 9/11, by the Twitter critic may have some truth...as you noted. But it would have been beneficial to see the previous four years of data, included with Bush's first term. It just gives us a better look at where momentum was, or was lost.
Thanks for sharing...I'll be off to look at the full set of charts you posted!