Washington (AP): Barack Obama focussed his campaign message against likely Republican nominee John McCain amid mounting signs that the historic monthslong battle with Hillary Rodham Clinton for the Democratic nomination was coming to a close.

Obama picked up another superdelegate, bringing him within a half delegate of erasing Clinton's once-substantial lead among the elected officials and party leaders whose votes will prove decisive in determining the Democratic presidential nominee. The trend showed that her financially strapped campaign is nearly over.

Obama's quiet, and increasing, confidence that the nomination is his was evident in his campaigning yesterday in Oregon, where he aimed his criticism at McCain and largely ignored his Democratic rival. He planned to continue campaigning in the state today.

"I'm gratified that we've got some superdelegates who are coming our way. And I think we've got a strong case to make that I will be a nominee that can pull the party together and take on John McCain," Obama told reporters in Woodburn, Oregon.

After a sometimes bitter and acrimonious campaign, the Democratic race entered its final weeks, with electoral math the deciding factor. Clinton, unlikely to be able to erase Obama's 1,860.5 to 1,698 lead in delegates, needs massive support from those superdelegates -- party leaders free to vote as they chose -- who have yet to declare their preference.

With Obama also unable to reach the 2,025 delegates needed to win the nomination based solely on elected delegates, that same group offered the key to his securing the party's stamp.