As the presidential race enters its final days, Iowa stands out as a question mark on the electoral map.
Strategists in both parties express confidence about winning the state and its six electoral votes, but few on either side are willing to guarantee a victory.
President Barack Obama won Iowa by almost 10 percentage points in 2008. But there is agreement here that the outcome is likely to be decided by just a few thousand votes, as it was in 2004, when President George W. Bush won the state, and 2000, when Al Gore won.
A new Wall Street Journal/NBC/Marist poll out Thursday showed Obama leading Mitt Romney by six points, but even Democrats admit that spread seems a bit optimistic.
That the Iowa race is coming down to a game of inches befits a state known for its intensely local brand of politics.
In Iowa, a state with just over 2 million registered voters, the little things still matter: small-town newspaper ads, person-to-person contact, radio spots that can be heard inside the cab of a John Deere.
In some ways, the Iowa race is a microcosm of the national one, a test of whether the fearsome Obama political operation can cobble together the votes to blunt a late-breaking spurt of enthusiasm for Romney heading into Election Day.
First lady Michelle Obama punctuated the tightness of the Iowa campaign on Monday at a campaign rally in Iowa City as she delivered a lengthy get-out-the-vote plea to about 800 denizens of the liberal college town.
Her husband's 140,000-vote margin of victory in 2008, she explained, was the equivalent of roughly 87 votes per precinct.
"So 87 votes," the first lady said. "That could mean just one vote on a block, just a couple votes in a neighborhood, just a single vote in an apartment building or a dorm room.
"So I want you to think about just a few more evenings on a phone bank, just a few more hours talking on doors," she urged the crowd. "You in this room alone can swing an entire precinct for Barack Obama. And if we win enough precincts we will win this state."
Mining crowds for votes and manpower
At the rally's conclusion, campaign volunteers marched a modest-sized group of audience members across the street to an early voting location inside the Iowa City Public Library, where they could register on the spot and cast their ballot.
The tactic of mining crowds for votes and manpower is an Obama campaign maneuver that dates back to the 2008 campaign, and staffers continue to use it to great effect.
A last-minute President Bill Clinton appearance in Council Bluffs on Wednesday drew 600 supporters, and the campaign promptly signed up 150 of them to work get-out-the-vote shifts on Election Day.
Campaign officials say their organizational presence around the state, with neighborhood teams embedded in tiny rural communities like Cresco (population 3,868) and Clarinda (population 5,572), gives them the power to hunt down low propensity voters in a way Romney's ad hoc field operation cannot.
As in other key states, the Romney campaign in Iowa is relying on the Republican National Committee to manage its get-out-the-vote program. Because of turmoil inside the libertarian-leaning Republican Party of Iowa, the RNC was forced to set up a "shadow party" to run its state-level field operations.
"All along we've believed having one-on-one conversations with voters will have an impact, because they do cut through the clutter," said Brad Anderson, the Obama campaign's state director in Iowa. "In the last couple weeks, the television airwaves are a mess, the mailboxes are full. It's these conversations that we have with voters in every part of the state, in rural Iowa, that the Romney campaign does not have the capacity to do."
Democrats in Des Moines also snickered at a Politico item this week that quoted a Romney official boasting that the "Branstad operation" -- that would be Iowa Gov. Terry Branstad -- would help propel them to victory.
Branstad's circle of advisers is well-regarded inside the Capitol building, and his approval rating is north of 50 percent, but the Republican governor does not have any kind of vaunted political machine at his disposal.