Campaigning a few miles from each other Friday, Barack Obama trained his eye on November and the GOP, while Hillary Rodham Clinton battled for her political life, trying to hang on a bit longer in hopes of denying him the Democratic presidential nomination.

Obama, increasingly confident that Clinton cannot overtake his lead, ignored her in his prepared remarks at a Portland-area workplace. Instead he pointedly criticized Republican Sen. John McCain's economic, health and Iraq policies, saying the probable GOP nominee would continue failed Bush administration priorities.

When asked about Clinton, Obama heaped more praise than criticism on the New York senator, continuing his efforts to avoid antagonizing her or her supporters. Speaking later with reporters, Obama hinted that he might help Clinton retire her campaign debt if he prevails.

Also campaigning in Portland, ahead of Oregon's May 20 primary, Clinton took the opposite tack, knowing she can't take on McCain unless she somehow derails Obama. At a round-table at Doernbecher Children's Hospital, she criticized Obama's health care plan for promising universal coverage to children but not adults.

"An artificial distinction between children and adults is unworkable," Clinton said. "You've got to have a seamless health care system which covers every single person. My plan does, my opponent's doesn't."

She added, "This is a big difference in this campaign. It's not a difference of politics so much as commitment. ... How can anyone run to be the Democratic nominee and not have a universal health care plan?"

Obama, a first-term Illinois senator, says he has not secured the Democratic nomination, even as party superdelegates continue to abandon Clinton, or their previously undeclared status, and endorse him. But his campaign increasingly looks like a general election affair, with him focusing on McCain and devoting two full days this week to Oregon, a perennial battleground state between the two parties.

Speaking to a few dozen employees of Vernier Software & Technology, which develops educational materials, Obama said McCain was "dead wrong when he said recently that he thinks our economy has made 'great progress' under George Bush. Is there anyone outside of Washington D.C., who could truly believe that?"

He rebuked McCain for supporting Bush's "tax cuts for the wealthiest Americans," a temporary halt to the federal gasoline tax and continued heavy U.S. presence in Iraq.

Obama did not mention Clinton until an employee asked about their respective health care plans. He acknowledged Clinton's criticisms, but said the government should not penalize low-income adults who choose not to buy health insurance even with a significant government subsidy.

When asked if he might make Clinton his running mate, Obama said it would be presumptuous to speculate because "I have not won this nomination yet."

"But I will say that she has shown herself to be an extraordinary candidate and an extraordinary public servant," he said. "She is hardworking, she is tough, she is very smart. And so I think she would be on anybody's list, short list, of vice presidential candidates."

He predicted Clinton will win the Kentucky and West Virginia primaries "by significant margins," although he will campaign in those states next week.

After stopping for lunch at Luis' Taqueria in Woodburn, Ore., Obama told reporters it was premature for him to talk with the Clinton camp about possibly helping her retire her multimillion-dollar campaign debt, much of it from Clinton's personal loans.

Asked if he might consider such a move later, Obama said: "Historically, after a campaign is done and you want to unify the party, particularly when you've had a strong opponent, you want to make sure that you're putting that opponent in a strong position so that they can work to win an election in November. And so obviously I'd want to have a broad-ranging discussion with Senator Clinton about how I could make her feel good about the process and have her on the team moving forward."

Meanwhile Friday, Clinton began airing an ad in Oregon in which former CIA operative Valerie Plame and her husband, former Ambassador Joseph Wilson, say the New York senator has the strongest plan to end the war in Iraq.

Clinton's top fundraisers and advisers said she would continue campaigning through the final primaries, believing voters in the remaining six contests deserve a voice in the nominating process.

Hassan Nemazee, co-chairman of her finance committee, said her fundraising in recent days had been sufficient to carry the campaign through the next several weeks. "There is no reason for her to stop now," Nemazee said.

The McCain campaign issued a lengthy rebuttal to Obama's remarks. It noted that Obama once supported a gas tax suspension, which Obama now calls a mistake. It accused him of seeking unwise hikes in taxes and spending.