Gerald Seib of the Wall Street Journal discusses their recent poll:

The poll found what they termed “unease” with Obama among undecided voters:

When voters were asked whether they could identify with the background and values of the two candidates, 58% said they could identify with Sen. McCain on that account, while 47% said the same of Sen. Obama. More than four in 10 said the Democratic contender doesn’t have values and a background they can identify with. . . .
“Obama is going to be the point person in this election,” says pollster Peter Hart, a Democrat who conducts the Wall Street Journal/NBC News poll along with Republican Neil Newhouse. “Voters want to answer a simple question: Is Barack Obama safe?”

Team Obama wants the election to be a referendum on President Bush (whose approval rating is 28%) and the Republican Party (which is losing by 11 points on the so-called “generic ballot” question). As Patrick Ruffini has said, Team McCain must make the election a referendum about Obama. This WSJ poll indicates that, so far, the McCain campaign has been successful in defining the battlefield to their advantage.