"If the major competitive states are split, we could be talking about a situation where one electoral vote matters," said Randall Adkins, a political science professor at the University of Nebraska at Omaha.
Only Nebraska and Maine divide their electoral votes, though the votes have never actually been split. Obama has opened a campaign office in Omaha to make a play for the electoral vote decided by results in the 2nd Congressional District, which would be essential to victory if the election ended in a 269-269 electoral tie, neither candidate reaching the mandatory 270 electoral votes.
Such a tie could happen, say Nebraska Democrats, if Obama and Republican were to take most of the states they're expected to win and if Iowa, Nevada and New Mexico were to switch from Republican to Democrat.
The Obama campaign started canvassing Omaha neighborhoods last month. John Berge, hired as director of Obama's Nebraska campaign, said that while some resources will go into the rest of the state, they'll be focused on the 2nd District.
Omaha, with about 400,000 people, lies in a congressional district of nearly 600,000. The city and suburbs have most of the state's black population and much of its population of Hispanics and other minorities, groups that national polls show favoring Obama.
The 2nd District gives Obama a small geographic area to target. Television ads aimed at Council Bluffs, Iowa, just across the river, already spill over onto Omaha networks.
Adkins isn't convinced that Obama can actually win Omaha's electoral vote. Republicans have a 15,000-voter advantage in the district - much less than in other parts of the state, but still formidable.
So far, McCain's effort in Nebraska is largely volunteer.
The Nebraska Republican Party is canvassing on his behalf, said executive director Matt Miltenberger. Volunteers are hitting thousands of households with information about McCain and state candidates, including 5,000 homes in the 2nd District, Miltenberger said.
"There will definitely be a McCain presence here," Miltenberger said.
Loree Bykerk, chair of the political science department at UNO, said some of the attention for Nebraska might be more a result of Obama "having more money that he knows what to do with."
However, Bykerk added, "if they're going through the trouble of setting up campaign offices in Nebraska, Alaska, Wyoming, maybe it is going to be close."
In Maine, which has gone Democratic in the last four presidential elections, the Republican ticket is seen as having a shot at carrying the northern 2nd District, but little chance of taking the 1st District or the state at large.
"It's largely rural, overwhelmingly white and certainly not liberal," University of Maine political scientist professor Mark Brewer said of the 2nd District, which is the largest geographically east of the Mississippi.
Professor Sandy Maisel, director of the Goldfarb Center for Public Affairs and Civic Engagement at Colby College, agreed that the 2nd District is more in play than the 1st, but would be "very surprised" if McCain took it.