The Democratic hopeful is trying to cut into's base in West Virginia. The state's demographics appear to favor Clinton, whose support is strongest among older white voters and blue-collar workers.
"When you're spending over $50 to fill up your car because the price of oil is four times what it was before Iraq, you're paying a price for this war," Obama said. "When Iraq is costing each household about $100 a month, you're paying a price for this war."
By linking the economy to the war, Obama is playing to his perceived strength as someone who spoke out against the war as a state lawmaker in Illinois. He has criticized Clinton for only recently opposing the war and said Thursday that her criticism of Republican's war policies lacks teeth.
"Her point would have been more compelling had she not joined Senator McCain in making the tragically ill-considered decision to vote for the Iraq war in the first place," Obama said to cheers.
It was the third consecutive day that Obama set aside his usual stump speech and delivered a more focused issue speech. He discussed race relations on Tuesday and the foreign policy consequences of the Iraq war Wednesday.
Obama has won more states than Clinton, leads in the popular vote and holds a nearly insurmountable lead in pledged delegates. But neither candidate can clinch the nomination without help from superdelegates, the party leaders who are not bound by any primary or caucus and are free to vote for whomever they choose. Clinton hopes a strong finish in the remaining primaries will persuade superdelegates to back her in a close race despite the delegate shortfall.
West Virginia holds its primary May 13. The economy is a key issue in West Virginia and Obama aides concede that Clinton is expected to perform well here.
"For what folks in this state have been spending on the Iraq war, we could be giving health care to nearly 450,000 of your neighbors, hiring nearly 30,000 new elementary school teachers, and making college more affordable for over 300,000 students," Obama said.
Obama was introduced at the University of Charleston by U.S. Sen. Jay Rockefeller, a West Virginia Democrat who played up Obama's blue-collar credentials and his familiarity with West Virginia's coal industry.
"He's a man who's worked for everything he's achieved. That's something I can't say," Rockefeller joked. He said Obama can see the world "through the eyes of those who are in the trenches every day struggling to make ends meet and who are fighting to keep their families together."