"Let me be clear, privatizing Social Security was a bad idea when George W. Bush proposed it, it's a bad idea today," Obama said. "That's why I stood up against this plan in the Senate and that's why I won't stand for it as president."
Bush proposed a Social Security plan in 2005 that focused on creating private accounts for younger workers, but it never came up for a vote in Congress. Democrats strongly opposed the idea and few Republicans embraced it.
Obama said McCain would push to raise the retirement age for collecting Social Security benefits or trim annual cost-of-living increases. Obama has rejected both ideas as solutions to the funding crisis projected for Social Security in favor of making higher-income workers pay more into the system.
"We have to protect Social Security for future generations without pushing the burden onto seniors who have earned the right to retire in dignity," he said.
McCain spokesman Tucker Bounds accused Obama of making "misinformed partisan attacks."
"John McCain has been clear about his belief that we must fix Social Security for future generations and keep our promises to today's retirees, but raising taxes should not be the answer to every problem," Bound said.
It was a day of coastal campaigning for the two Democrats still competing for the party's presidential nomination.
Obama was in Oregon, where he is favored to win the state's presidential primary on Tuesday. Hillary Rodham Clinton spent a second straight day in Kentucky, where she is favored to win when its voters head to the polls the same day.
She attended worship services at a Methodist church in Bowling Green, and happily sang hymns and joined in Bible readings. But her smile faded when the pastor launched into a sermon about adultery, asking his congregants whether the devil had ever whispered over their shoulders in their marriages.
Her mood appeared to brighten by the time she arrived for a rally at West Kentucky University.
"Now, my opponent said the other day he wasn't coming back, so I've got the whole state to myself," Clinton said, sounding happy not to be sharing the Kentucky spotlight. "What a treat."
Obama, the front-runner for the nomination, has begun casting himself as the inevitable nominee and using his time to distinguish himself from McCain as he pivots toward the fall campaign. He has scheduled appearances later this week in Iowa and Florida, two key swing states.
Later Sunday, Obama was headed for a big outdoor rally in Portland and a second town meeting in Pendleton before a late flight to Montana for a day of campaigning on Monday.
During the meeting with seniors, Obama was asked why McCain seems to have avoided the enormous press scrutiny the Democrats have gotten.
Obama said McCain has benefited from a Republican nomination process that ended early while the Democratic race continues. He said the attention both candidates receive will grow more intense as the race settles into an Obama-McCain contest.
"It's very understandable that the press has focused on myself and Senator Clinton because it's been a pretty exciting race," Obama said. "The fact is that the press will submit him to the same scrutiny they are giving to me."
"People will lift the hood and kick the tires with John McCain, just like they do with me," he said, who traveled Sunday with his wife, Michelle.
---
Associated Press writer Sara Kugler in Bowling Green, Ky., contributed to this report.
