But McCain, he contended, "has got a tougher job. He's got to unmask Barack" as lacking the credentials to handle the job of president.
Obama's campaign won an agreement from the McCain camp to have the first debate center on foreign policy issues. The presidential debate commission had originally proposed that domestic policy be the topic of the questions from moderator Jim Lehrer of PBS.
Still, much of the discussion is expected to focus on global ramifications of economic issues, including turmoil in financial markets and energy supplies.
Rove, in a Wall Street Journal commentary yesterday, said the debates start out on more comfortable turf for McCain, who has "a sizable poll lead on who'd be a better commander in chief." But he warned that McCain's decision to avoid extensive pre-debate rest and rehearsals was "dangerous."
During the primary debates, neither man was regarded as a superior debater, though McCain is generally seen as more able to offer succinct responses than Obama.
Democratic Rep. Rahm Emanuel of Chicago, an Obama adviser, said viewers need to see Obama tonight as someone "who is ready to be president of the United States."
"That's what's important. It's not any individual question," Emanuel said.
Both campaigns, and the news media, will be parsing each answer, however, for possible gaffes or inconsistencies.
Strategists made the point that post-debate opinion shifts are common, with voters concluding afterward that the candidate who seemed to "lose" the debate had actually done better.
"The story line of the coverage afterwards can do almost as much to shape perception as much as the debate itself," according to Rove.
In the 2000 election, "post-debate media spin may have been more favorable to Bush," who "lost" to Al Gore in a debate-night poll by a 48-41 margin but wound up tied in surveys conducted three days later, according to an analysis by Gallup Poll senior editor Lydia Saad.
In 2004, Democrat John Kerry cut Bush's lead from 11 percentage points to two after the first debate. Bush went on to win the popular vote by three points.
"The 2008 debates could be an important factor in shifting voter preferences decisively," said Saad. "With so much economic uncertainty and political activity going on, however, it may be impossible to disentangle the effect of the debates from the effect of other news events on voter preferences at this critical time."
