The final Pew Research Center poll of the 2008 presidential election gives Barack Obama a 49 to 42 percent lead over his rival, John McCain. Though still a significant lead, it's suddenly a much tighter race than Obama's 15-point lead from last week.
There are two things closing the gap, says Andrew Kohut of the Pew Research Center. First, McCain has made some gains among whites, independents and middle-income voters. But the other boost he's enjoying comes from narrowing the pool of responses from registered voters to likely voters.
Typically, Republican voters tend to vote more regularly than some Democratic voting groups — particularly young people and blacks, Kohut says. So while turnout is up among those groups, it's also up across the board — giving Republicans a boost when the poll focuses on likely voters.
It may not be as strong as a week ago, but Obama's lead in the Pew poll agrees with several national polls that have him ahead by a 5-point average.
"This is a pretty substantial lead," Kohut says. "We haven't had a lead for a candidate this substantial since 1996, when President Clinton was leading Sen. Dole in the final weekend of the campaign."
But that's not the only poll data leaning in Obama's favor.
The strength of each candidate's support among likely voters has historically been a significant indicator of a race's outcome. According to the Pew poll, 36 percent of likely voters say they strongly support Obama, while only 24 percent say they are strong supporters of McCain.
"Typically," Kohut says, "if we look back to elections going back to 1960, invariably the candidate with the stronger support wins the election."
Despite the numbers, Kohut warns, you can't take voters for granted. But he admits that it would take something pretty big to upend what most of the polls are showing. "But in an election where the unexpected is the expected," Kohut teases, "who knows?"