If you look beneath the graph's horizontal scale, you'll see that these data are actually monthly unemployment rates for October of each year. (The graph doesn't show annual employment, as one might have expected from a year-by-year display.)
Presumably the reason for picking October is that
it allowed Bachmann to highlight the 10.1% spike in unemployment that occurred in October of 2009. (The annual unemployment figure for that year was a less dramatic 9.3%.)
Noreen Malone at Slate has noted the lack of labels for the even years, which helps to create a sense of separation between the two administrations. But personally, I can't see that the data support such a clean separation. Here is what you get when you look month by month:
I was also amused to notice that in Bachmann's graph, President Bush's bars were squeezed to the left of his yearly slots, while Obama's bars were squeezed to the right of his yearly slots. The effect of this was to enlarge the gap of white space between the red bars and the blue bars - again enhancing the sense of separation between the two administrations. With a regular pattern of small gaps to the left, and a regular pattern of small gaps to the right, the large gap "does the work" of distinguishing between the two presidents. Nice of her team to save us the trouble.
Recently I laughed out loud when I saw Chris Matthews losing it while interviewing Tea Party strategist Sal Russo about a speech Bachmann had given, in which she suggested that the Founders worked tirelessly to eliminate slavery. Bachmann had said:
But we also know that the very Founders that wrote those documents worked tirelessly until slavery was no more in the United States.
Matthews went ballistic about this apparent attempt to whitewash the story of the founding of the nation. The Constitution was ratified around 1788, and slavery was abolished around 1865; so given that 1865 - 1788 = 77, it's pretty hard to imagine that the Founders "worked tirelessly until slavery was no more in the United States." Many have suggested that Bachmann is ignorant of history; maybe she's just ignorant of subtraction.
Bachmann's speech posed another math puzzle:
Do you realize it's been 21 generations that America has survived?As soon as I heard this, I started scratching my head because I normally think of a generation as being about 25 years long - and 21 times 25 is going to be something like 500 years. Yet I had always thought of America as being more like two hundred and some years old.
Could Bachmann be referring to Columbus? The fuller quote is:
Do you realize it's been 21 generations that America has survived? For 21 [generations], we've passed the torch of liberty from one generation successfully to the next.
It's hard to believe this refers to Columbus, who as I understand it was an Italian. But then again, I don't know what the alternative is. Wasn't "the torch of liberty" lit sometime around 1776? If so, then (2011 - 1776)/21 = 11 or thereabouts...and a generation can't be 11 years long.
So I don't know if she's fuzzy on history or fuzzy on math. She's certainly fuzzy on something.
Sources: I found annual unemployment numbers at http://www.bls.gov/cps/prev_yrs.htm. For monthly numbers, I used the query tool at http://data.bls.gov/pdq/querytool.jsp?survey=ln to find the following (paste into Word and use the Convert Text to Table command):