Like President Bush, the high command of Sen. Barack Obama’s (D-Ill.) presidential campaign claims to pay no attention to unfavorable national polls, asserting that what counts is its aggressive “ground game” in 18 key battleground states.

[IMGCAP(1)]Key Obama advisers say that they hope to match or exceed the “tremendous” Bush field operation of 2004, which increased Republican turnout by 12 million votes over 2000, beating Democrats’ 8 million increase.

As an example, Obama advisers say they’ve identified 600,000 African- Americans who did not vote in Florida in 2004 and hope to score big among 900,000 young people who did not vote. Bush beat Sen. John Kerry (D-Mass.) in Florida by 381,000 votes in 2004.

And in Pennsylvania, where Kerry won by 145,000, Obama aides said Democrats have registered 360,000 new voters while Republicans have lost 60,000, for a net shift of 420,000 in the Democrats’ direction.

“I never read the Gallup daily tracking poll,” one Obama adviser said, concentrating instead on trends in voter enthusiasm and the preferences of independent women, regarded by both sides as a key swing group this year.

On the other hand, a high-ranking official of Sen. John McCain’s (R-Ariz.) campaign told me that the Gallup track — showing a McCain lead of 2 points for the first time on Tuesday — was evidence that Obama was losing support, even during his own national convention.

Some GOP pros acknowledge that Obama’s well-organized and superbly led campaign has a two-month head start on McCain in field organization, although a top McCain staffer said “we learned in 2002 and 2004 how to micro-target, reach out to voters and get them to the polls, and there’s no evidence that the Democrats know how to do it as well as we can.”

The McCain chieftain also recounted with some glee how continuing friction between the Obama and Clinton campaigns is sapping Democratic unity and how some key state polls are moving in McCain’s direction.

Indeed, on Tuesday, even as top Obama and Clinton officials were denying any discord, former President Bill Clinton told foreign diplomats that voters might well prefer an unnamed “Candidate Y” with whom they partially disagreed — but who could “deliver” — to a “Candidate X” with whom they fully agreed, but couldn’t deliver.

He denied this hypothetical had anything to do with the Obama-McCain race, but practically no one believed him — especially because close associates of his were loudly complaining that the Obama campaign was “dissing” the ex-president by not allowing him to speak in prime time on Wednesday.

And, while Sen. Hillary Rodham Clinton (D-N.Y.) made a strong case Tuesday night why she prefers Obama to McCain on policy grounds, she did not say a word in praise of his leadership abilities — or even his eloquence and ability to inspire new voters.

The McCain campaign has been running ads exploiting old Clinton criticisms of Obama and the defection of at least one attractive Clinton delegate to McCain. Cable channels have found other Clinton delegates still skeptical of Obama and unhappy that Sen. Clinton was not Obama’s vice presidential nominee.

Obama reportedly bypassed Clinton because preliminary vetting turned up embarrassing names in donor lists to Bill Clinton’s foundation and library and because Obama believed there could not be a “White House with three presidents,” meaning himself, Hillary and Bill Clinton.

Still, the Obama high command exudes confidence about what’s likely to happen in November, claiming that the very success of Bush’s 2004 efforts limits McCain’s ability to grow GOP turnout — which he must to do match Obama’s registration, voter contact and turnout efforts.

Obama aides cite an ABC-Washington Post poll this week showing that 95 percent of Obama voters describe themselves as “enthusiastic,” versus 86 percent for McCain, and 52 percent as “very enthusiastic” vs. only 28 percent for McCain.

Women split for Obama, 55 percent to 37 percent, while Kerry won them by only 51-48. And white women favor Obama 50-42, whereas Kerry lost them, 55-44.

Former Democratic National Committee Executive Director Mark Siegel pointed out, moreover, that 2004 turnout models may be outdated. Only 30 percent of under-30-year-olds voted in 2004, he noted, whereas 50 percent may vote this year, and only 51 percent of African-Americans turned out, whereas 65 percent or 70 percent may vote this year — all to Obama’s benefit.

On the other hand, former Bush political guru Karl Rove came up with figures showing that enthusiasm for Obama is flagging among young people as he “goes negative” and seems increasingly to be an “ordinary politician.”

And Rove cited registration figures in Florida showing a net pickup of only 24,000 for Democrats and 88,000 for independents this year — not enough to overcome the 2004 GOP advantage.

Meantime, state polls in the 18 most-contested states do not show an overwhelming surge to Obama. New Quinnipiac polls show gains by McCain in Florida and Ohio, while Obama is holding a 7-point lead in Pennsylvania.

In a time of deep dissatisfaction with the status quo and with the incumbent GOP administration, Obama is leading in Realclearpolitics.com’s electoral vote tally just 228 to 185, with states holding 125 electoral votes polling as tossups.

The tossups include Virginia, Michigan, Colorado, Nevada, New Mexico, New Hampshire, Minnesota and North Carolina.

McCain is more than 5 points ahead — but not 10 — in Missouri, Georgia and North Dakota, as Obama is in Pennsylvania, Iowa, Wisconsin and Oregon.

Of course, all these calculations are based on old models. Obama’s team thinks its candidate and its ground operation can break the mold and make history.