President Obama made his second visit in three months to this battleground state yesterday to return fire on Republican attacks blaming him for rising gas prices - a potentially major point of contention in the November election. Noting that his administration has helped propel decreased foreign oil dependence and stepped up domestic oil production in recent months, Obama said rising gas prices are a function of global markets, particularly instability in Iran, that no president can fully control. Obama said the country’s best path to lower gas prices was an all-of-the-above strategy that includes a focus on expanding sustainable energy and ending the $4 billion in annual subsidies given to the oil industry. .