Here's my NEWSWEEK colleague Holly Bailey with a report from the McCain caravan in Pennsylvania, where the Arizona senator sought this morning to establish greater credibility on 2008's top issue: the struggling economy. Read my earlier dispatch from last week's Brooklyn event here.

PITTSBURGH, Penn.--For the third time in as many weeks, John McCain gave what was billed as a major speech on the economy, trying to regain control of a subject that he has bluntly admitted is not one of his strengths. Speaking at Carnegie Mellon University in Pittsburgh, McCain laid out a series of proposals aimed at short term relief from the nation's troubled economy, including a lifting of the federal excise tax on gasoline between Memorial Day and Labor Day. "The effect will be an immediate economic stimulus-taking a few dollars off the price of a tank of gas every time a family, a farmer or trucker stops to fill up," McCain said.

The senator also called for a series of long term fixes, including doubling the tax exception for dependent children. He proposed cutting the federal deficit by, among other things, asking wealthier Medicare recipients to pay more for their prescription drugs. He said he would initiate a one year "pause" on discretionary spending among government agencies that don't deal with the military or veterans in order to review spending and reiterated his campaign promise to veto pork laden congressional bills. He also repeated his calls for the government to investigate those behind the housing crisis. "Something is seriously wrong when the American people are left to bear the consequences of reckless corporate conduct," McCain declared.

Today's speech (like the previous two) was aimed at building up McCain's leadership when it comes to handling the nation's troubled economy. In some ways, McCain is trying to undo the damage he did his own campaign, when he bluntly admitted last year that the economy wasn't exactly his strong suit.

 "The issue of economics is not something I've understood as well as I should," McCain told reporters on his Straight Talk Express a few weeks before the New Hampshire primary, according to the Boston Globe. "I've got (Alan) Greenspan's book." It's a quote that the presumptive Republican presidential nominee has been trying to live down ever since, especially as the shaky economy has become one of the key issues heading into the general election.

McCain has struggled to find his voice on the subject. Until recently, the presumptive Republican presidential nominee didn't say much about the economy at town halls, beyond repeating the familiar GOP mantra of fighting pork and extending President Bush's tax cuts. Three weeks ago in California, McCain made his first big foray into the debate over what to do about the housing crisis, arguing that the government shouldn't be quick to intervene on behalf of affected borrowers and lenders. "It is not the duty of government to bail out and reward those who act irresponsibly, whether they are big banks or small borrowers," McCain said, in remarks that at least one of his top supporters found lacking. "I would give Senator McCain an incomplete," Sen. Mel Martinez, who served as Bush's first Secretary of Housing and Urban Development, told CNN.

Last week, McCain tried again, this time striking a more compassionate tone. He called for the federal government to come to the aid of those in danger of losing their home by helping needy homeowners falling behind on their loans to refinance their mortgages and apply for loans backed by the Federal Housing Administration. "Let me make it clear that in these challenging times, I am committed to using all the resources of this government and great nation to create opportunity and make sure that every deserving American has a good job and can achieve their American dream," McCain declared. He and his advisers rejected charges that he had shifted his message, arguing that his plan was aimed at homeowners, not lenders, and was completely in line with what he'd said in California. "I said there shouldn't be a broad government bailout," the senator told reporters on his plane last week.

Today's speech didn't offer many specifics on how McCain actually plans to accomplish or pay for his proposals-few of these campaign speeches, whether from Democrats or Republicans, actually do. Notably, the senator didn't once mention the war in Iraq, which he admitted to reporters as recently as yesterday has had an effect on the economy. (If we weren't there, McCain said, "The cost to our country would be greater.") What today's speech did do for McCain is to allow him to talk with confidence about broad themes he actually is fluent on: his war against pork barrel spending, his push to control excessive government spending. Even one of his biggest proposals of the day-his push for Medicare recipients with incomes above $160,000 to bear more of the burden of their drug benefits-isn't new. Going against Bush and leaders of his party, McCain voted against the bill that created the benefit in 2003, arguing it was too expensive. Will it be enough to convince voters that McCain is the man who can be tasked with guiding the nation through troubled economic times? Only time will tell.