That's because of drilling on private lands. Drilling on federal lands is down under Obama, and much of that oil is less expensive and easier to extract. Also, Obama strongly opposes gas tax relief to help people with high gas prices. When Obama entered, gas was $1.78 a gallon. Now it's almost double that.
That $1.78 a gallon was a momentary drop from a $4.00 a gallon high
We were in an economic collapse at the time and gas prices plummeted as a result. Not something to brag about
I agree that part of the 2008 drop was due to the economy, but it's important to note that there was a very significant price drop after Bush lifted the ban on offshore drilling(which Obama re-instated).
Historical Gas Price Charts - GasBuddy.com
In July 2008, gas prices were at their peak. In July 16, 2008, Bush lifts the moratorium on drilling and prices plummet. July 16, 2008 is at just about the vertex of gas prices on the graph. And this was before the Bear Sterns collapse. Yes, it went down a lot after that, but there was absolutely a role played by lifting the ban.
Then, in February 2009, the Obama administration delays these new changes and makes drilling much, much harder, especially after the BP Oil Spill (of course, the people in Louisiana, most affected by the spill, strongly support offshore drilling to help their economy, but Obama says no).
Obama Administration Imposes Five-Year Drilling Ban on Majority of Offshore Areas - House Committee on Natural Resources