GOP pollster Bill McInturff said in a memo released by the McCain campaign that the Arizona senator “has made impressive strides over the last week of tracking.” He added that the race against Democrat Sen. Barack Obama (Ill.) in both red and blue states is closer than is currently perceived.

The pollster said that the number the campaign is watching is “Sen. Obama’s level of support and the margin difference between the two candidates.”

“As other public polls begin to show Sen. Obama dropping below 50 percent and the margin over McCain beginning to approach margin of error with a week left, all signs say we are headed to an election that may easily be too close to call by next Tuesday,” he said.

McInturff noted that he is seeing “significant shifts in battleground states,” with “gains” that are sustainable with “non-college men,” rural voters of both genders, anti-abortion voters and “most encouragingly...we are beginning to once again get over a 20 percent chunk of the vote among soft Democrats.”

The pollster said a subgroup the campaign has long targeted, known to them as “Walmart women” and identified as not having a college degree and residing in households that make less than $60,000 a year, “are also swinging back solidly in our direction.”

He added that the campaign is “witnessing an impressive ‘pop’ with Independent voters.”

McInturff said the campaign’s focus on taxes, Obama’s running mate Sen. Joseph Biden’s (Del.) comment about Obama being tested by an international crisis and an emphasis on “Joe the Plumber” is largely responsible for what they see as tightening polls.

“This has been the week where ‘Joe the Plumber’ has literally become a household name,” the pollster wrote. “An astounding 59 percent of voters in these battleground states have heard ‘a lot’ about this story, 83 percent have heard ‘a lot’ or ‘some’ about this episode.”

McInturff said their responses indicate record turnout levels not seen since the elections of 1960 and 1968, which “in today’s terms, that could mean breaking the barrier of 130 million voters.”

“There is simply no model that begins to know or predict the composition of the electorate at this level of turn-out,” he said. “My own view…and our own weights in our surveys…reflect a belief that African American turn-out will be at historic levels, there will be a significant boost with voters 18 to 29 years old, yet the overall high level of turn-out will begin to mute the increase in the percentage these sub-groups represent in the overall electorate.”

He added that there are a higher number of “refuse to respond” voters than in previous elections, but he believes they are voters that break overwhelmingly toward the Republican candidate. Those voters are identified by McInturff as similar to those who broke toward Obama’s primary opponent, Sen. Hillary Rodham Clinton (N.Y.), in the closing, rural states during the nomination contest.

The numbers McInturff provided on this point could point to what many analysts describe as “the Bradley effect,” where poll respondents decline to say or lie to pollsters about whether they will vote for a black candidate.

Lastly, McInturff said Obama is maxing out with black voters, leaving the “refuse to respond” or undecided voters comprised only of Latino and white voters. That means, the pollster said, that Obama is maxing out with the numbers he is getting in polls, leaving McCain in a position to effectively sweep the remaining undecideds.

“This puts any number of historically red states very much ‘in play’ and much more competitive than is generally believed by the media,” McInturff wrote. “But critically, as Obama drops below 50 percent in other blue states, some of these states may also be coming back in play as well.”

The Obama campaign has consistently said it expects the race to tighten, urging its supporters to not rest on the strength of poll numbers.

As of Tuesday night, Obama was leading McCain in the RealClearPolitics average of polls by 6.7 percent, and the average of polls in the states put the Democrat in the lead in Electoral College votes 306 to 157.