Fuzzy math

It is understandable if you are confused about the race for the White House. Some headlines say President Obama "has a solid lead" while others declare, "Obama's rating falls."

Things got strange on May 16 when pollsters with the left-leaning New York Times and the right-leaning Fox News appeared to have switched reputations: A CBS News/New York Times poll gave Mitt Romney a 46 percent to 43 percent lead over Obama while a Fox News poll anointed Obama the leader by 7 points.

Confused? Pollster Scott Rasmussen has this advice: "Just glance at today's polls and then move along. Then after Labor Day I would begin to focus more on the horse race numbers." That will be after each party's conventions, after Romney has picked his running mate, and about the time of the debates.

For now, Rasmussen discounts a lot of the current polls because many of them questioned registered voters. The not-so-well-kept secret in American politics is that many registered voters don't exercise their voting right. This skews polls because they measure a bigger pool of voters than will actually show up-and many of those no-shows, according to Rasmussen, are younger voters who lean Democratic.

Four years ago John McCain won the majority of voters over 40 while Obama won the election with the votes of people under 40. Early indicators suggest fewer of these voters, their enthusiasm reduced, will go to the polls this time around, Rasmussen says. Accurate polls survey likely voters, and likely voters are easier to identify closer to Election Day.

But that doesn't mean readers can't pick out interesting nuggets from the present parade of polls. The Fox News poll favorable to Obama also reveals that Romney tops Obama by 6 percentage points among voters who say they are "extremely" interested in the election. Those people probably will turn into the fall's likely voters.

For now, Rasmussen recommends focusing on two numbers that have historically been reliable markers of what to expect in an election: a sitting president's job approval rating and how people feel about the economy.

In 2004 George W. Bush's approval rating stayed anchored around 50 percent, and on Election Day he received just over 50 percent of the vote. Obama's job approval rating this year has hovered consistently in the 46 percent to 48 percent range in several polls. "If his numbers end up there," Rasmussen says, "he will get just under 50 percent of the vote, and that could make it a very close election."

And one place where the divergent New York Times and Fox News polls agree: People think the economy stinks. In the New York Times poll 67 percent said the economy is in bad shape while in the Fox poll just 11 percent rated the economy positively. Both are bad signs for any incumbent. When asked by Fox what they thought Obama did to help the economy, 43 percent said, "Nothing."

Rasmussen says that, as the campaign moves through October, savvy observers should focus on polls in specific swing states as much as national polls.

A May 24 NBC News poll shows that Obama leads in Florida, Ohio, and Virginia. But the 12-point lead Obama enjoyed in Ohio in March has been cut in half, while his 17-point March lead in Virginia is now down to just 4 points. Meanwhile in North Carolina, where Obama won by less than 6 points in 2008, the president trails Romney by 8 points. With that state slipping out of reach, Obama may wish he were going somewhere other than Charlotte, N.C., for this fall's Democratic convention.