By Charles Mahtesian
The presidential race has narrowed to a core of nine states, a collection of margin-of-error battlegrounds spread across nearly every region.
From New Hampshire in the Northeast to Nevada in the Rocky Mountain West, there is little disagreement between the two campaigns about the places where the election will be won and lost. Aside from those two swing states, there are seven others: Colorado, Florida, Iowa, North Carolina, Ohio, Virginia and Wisconsin.
Some of them are familiar presidential battlegrounds, accustomed to playing a pivotal role every four years. Others are relative newcomers to the swing state roster. Every one of them was carried by President Barack Obama in 2008.
According to interviews with campaign officials and strategists, here's the state of play and the forces at work in the nine states:
With nine electoral votes, Colorado is the biggest prize in the Mountain West. That helps explains why, for the two weeks preceding the conventions, two of the nation's top five media markets in terms of ad buys were Denver and Colorado Springs.
The Romney formula depends on turning out the GOP base, especially on the energy-oriented Western Slope and in El Paso County's Colorado Springs, home to a politically active evangelical Christian community and a heavy military influence. This year, the expectation among Republicans is that Romney will also gain more traction in the Denver suburbs than John McCain.
The Obama strategy closely resembles the one successfully employed by Democratic Sen. Michael Bennet in 2010. Bennet ran well among Hispanics and benefited from an enormous gender gap — 17 points, according to exit polls. The same themes Bennet used — notably abortion rights and contraception — have been put to use again in Colorado and were underscored at the Democratic convention in Charlotte last week.
There's a reason the president campaigned in Colorado with Sandra Fluke in early August, and why he'll be back again later this week.
With its 29 electoral votes, Florida is essential for Romney.
The good news is that Republicans control the levers of power in the state thanks to their domination in recent elections — and the state party is one of the GOP's best. Still, Democrats hold a nearly 450,000 voter registration advantage.
This year, even as debates over Medicare and Israel have added a level of volatility to the presidential race there, many of the underlying fundamentals remain the same.
South Florida — namely populous Broward, Miami-Dade and Palm Beach counties — turned in big margins for Obama in 2008, which makes the I-4 corridor between Tampa and Orlando all the more important.
At one end, Tampa's Hillsborough County is one of the nation's top bellwethers: Since 1960, no presidential candidate has won Florida without carrying it.
Both sides are paying close attention to the swing county: The GOP went so far as to hold its national convention there, and Obama has visited at least twice already this year, not including his visit Saturday to nearby St. Petersburg.
At the other end of I-4, Romney needs to improve on the performance of McCain, who was blown out in Orlando's populous Orange County in 2008 after the race there was decided by razor-thin margins in 2000 and 2004. But the growth of the non-Cuban Hispanic population in the area — most notably, the Democratic-voting Puerto Rican population — has altered the political equation over the past decade and made Romney's Hispanic gap all the more glaring.
Barack Obama's 9 percentage-point Iowa win in 2008 obscured the voting habits of a state that is far more competitive than it appears. Iowa was one of just two that flipped from Al Gore in 2000 to George W. Bush in 2004, and in each election, the result was decided by less than a percentage point. Then, two years after Obama's victory, the GOP won up and down the ticket in a rout.
Iowa's competitiveness can be measured by how much time the president has spent there over the past month. Obama took a three-day bus tour through the state in early August and returned the day after his nomination acceptance speech last week. All for a state that offers just six electoral votes.
The ad buys are another sign of the tightness. In the two weeks prior to the GOP convention, the Des Moines, Quad Cities, Sioux City and Cedar Rapids media markets were drenched in ads.
The conservative western part of the state — think of it as Rep. Steve King Country — is where Romney figures to run best. The GOP is also counting on Romney and running mate Paul Ryan to cut into Obama's margins among Catholics – about a quarter of the electorate — in areas like Dubuque as a result of tensions surrounding the federal mandate to cover contraceptive services in health plans.
Voter registration figures are a promising sign for the GOP. Just before the 2008 election, Democrats had a 106,000-voter advantage. According to the most recent figures — bolstered in part by the competitive January caucuses, which led many independents to register as Republicans so they could vote — the GOP has a 22,000-voter edge.
But there are two factors working to the president's advantage. Obama has a unique relationship with Iowa, the state that launched his bid in 2008 and where he's been to all 99 counties. Then there's the unemployment rate — 5.3 percent in July, lower than all but five other states.
The president has led in every public poll there this year. Still, in the state with the nation's highest unemployment rate, there are no guarantees.
Obama is running well with Hispanic voters, whose numbers have exploded in Nevada over the past decade, and he will have benefit of Sen. Harry Reid's machine. Two X factors could also work to Obama's advantage in a tight race: separate ballot lines for former New Mexico Gov. Gary Johnson, who's running as a Libertarian, and for "None of the above."
For Romney, whose numbers have been improving in Nevada, the state's significant Mormon population will be an asset. And the Republican National Committee and Team Romney have done a solid job in attempting to overcome the state party's circus sideshow.
In the end, the state's two most populous counties will decide the outcome. Romney must pare down Obama's winning margin in Las Vegas's Clark County, where two-thirds of the Nevada vote was cast in 2008, and must dramatically improve on McCain's anemic showing in Reno's Washoe County battleground. Obama won both comfortably in 2008.
The smallest swing state prize with just four electoral votes, New Hampshire has been decided by less than 10,000 votes in three of the last five presidential elections.
Obama's 2008 victory there was not one of those close calls: his 54 percent to 44 percent victory was the biggest margin in the state since George H.W. Bush thrashed Michael Dukakis in 1988.
While Obama has led in nearly every public poll taken this year, New Hampshire took a sharp turn to the right in the 2010 elections. That and the fact that Romney has a home in Wolfeboro have contributed to GOP optimism that the former governor of neighboring Massachusetts has a good chance of stalling Obama's fine-tuned New Hampshire machine.
What to watch for? The gender gap. The traditional GOP disadvantage with female voters is especially pronounced for Romney there. And New Hampshire Democrats will have female nominees for governor and for both of the state's congressional seats.
Of all the battleground states, this is the one Republicans are most confident will return to the fold.
They point to a handful of polls showing Romney in the lead and also to the May ballot measure banning same-sex marriage, which puts the state at odds with the Democratic Party platform and the president.
And that's not all. Not much has gone right for Democrats since 2008, when the Obama campaign put together a remarkable ground game and caught the GOP sleeping. In 2010, though, Republicans made big gains by riding a wave that put the GOP in control of the state Legislature for the first time in more than a century. This year, the state Democratic Party has been embroiled in scandal and unpopular Democratic Gov. Bev Perdue declined to run for reelection.
African-American turnout will be critical this fall, and so will the performance of the state's two biggest counties: Mecklenburg County, where Democrats recently held their convention in Charlotte, and Raleigh's fast-growing and Democratic-trending Wake County. Obama won both by big margins in 2008.
The auto industry bailout is a key issue in Ohio, central to the Obama message there, and it hashelped to boost the president to a slim, consistent lead in most public polls.
The same polls suggest two areas that Romney needs to address: His advantage with men is smaller than elsewhere, and his deficit among women is larger.
In terms of the state map, Obama is likely to again do well in the populous urban counties, with Cleveland's Cuyahoga County expected to provide him with another big margin.
Romney can be expected to carry much of the state's western half and also southeastern Ohio, where the administration's stance toward coal has been unpopular.
Two counties in particular could play especially important roles. Romney can't afford to get crushed like McCain was in Columbus's Franklin County — the state's second largest after Cuyahoga. And he'll need to improve on McCain's performance in Cincinnati's Hamilton County, which flipped from a 53-47 Bush win in 2004 to a 53-46 Obama win in 2008.
With the 2008 election, Virginia made the leap from reliably Republican in presidential elections to swing-state status.
From the recent ad buys in the Roanoke-Lynchburg and Richmond markets to the frequent candidate visits, there's every sign the state will be close to the end.
There are several regions to watch, beginning with the D.C. suburbs of Northern Virginia, where the Obama campaign is making a play for swingfemale voters and independents turned off by GOP rhetoric and legislative action on social issues. Maximizing African-American turnout is also critical to Democratic chances — keep any eye on the Norfolk-Virginia Beach-Newport News area — a military-heavy part of the state with a high percentage of African-Americans.
Wisconsin is a late addition to the battleground list, a state that has surfaced on the GOP radar as a result of the dramatic recall victory by GOP Gov. Scott Walker and the pick of Rep. Paul Ryan as Romney's running mate.
It wasn't originally among the group of eight swing states in which the Romney campaign made its first general election ad buy, but on Friday ads hits the airwaves there, too.
While Wisconsin hasn't gone Republican at the presidential level since 1984 — and Obama has led in most polls there this year — there are signs of tightening since Ryan joined the GOP ticket. Four separate polls over thepast three weeks put the race within the margin of error.
It's not entirely unexpected. Putting aside Obama's big 14-point win there in 2008, the state was decided by less than a percentage point in 2000 and 2004. In 2010, the state produced a blowout win for the GOP up and down the ticket, followed by Walker's recall victory in June.
CORRECTION: The story has been updated to reflect that the last year Wisconsin voted Republican at the presidential level was 1984.
Charles Mahtesian is a reporter for POLITICO.com. POLITICO and ABC News 4 have partnered for the 2012 presidential campaign cycle.