Republican John McCain concentrated on the more conservative areas of Pennsylvania while Democrat Barack Obama pressed his case in the suburbs of Philadelphia, as the presidential campaigns brought their economic messages to the Keystone State on Tuesday.

With a week to go before election day, Pennsylvania is living up to its nickname as the political keystone for both camps. It is the state where Mr McCain is waging a vigorous campaign to capture what are usually Democratic electoral votes while the Obama camp has made a special trip back here to cement what polls show is a strong lead.