Obama is almost certain to win in Las Vegas and Clark County, where organized labor representing casino workers is strong and Democrats hold a 92,200-voter advantage. But even there, more than 100,000 voters are registered with no party preference.
The McCain-Palin ticket will probably win in rural parts of the state.
That means the Carson City-Reno-Sparks area could tip the balance. Republicans hold an edge, 97,000 voters to 89,000 Democrats, in the area encompassing Carson City and Washoe County, where Reno and Sparks are located.
"Washoe County is where it is going to be decided," said political scientist David Damore, of the University of Nevada at Las Vegas.
Obama and McCain both are airing television ads here. Obama is attacking McCain for supporting nuclear waste storage at Yucca Mountain -- not a popular stand in the Silver State. McCain's ads charge that Obama intends to raise taxes, also unpopular in a state with no income tax. Obama has vowed to raise taxes only for the wealthiest Americans.
Like Republicans, Democrats view Reno, Sparks and Carson City as battleground cities. The union UNITE-Here, which represents casino workers, has undertaken a significant independent campaign in northern Nevada. It has targeted roughly 35,000 voters, most of whom have Spanish surnames.
"If you don't move the needle in Washoe County, it undercuts what you can do in Las Vegas," said Jack Gribbon, the organizer overseeing the union's independent campaign.
In her remarks, Palin delivered several feel-good lines: "America is an exceptional country and you are all exceptional Americans." Perhaps she aimed to differentiate herself from Obama, who sometimes talks about "ordinary Americans."
She also repeated two of her most popular lines: that she turned down federal earmarks for the "bridge to nowhere" and that she put the state-owned jet on EBay. By the time Palin canceled the bridge between Ketchikan and its island airport, it had become clear Congress would not pay for it. Alaska did take the money that had been earmarked for the bridge and spent it elsewhere. And the plane failed to sell on EBay; a broker later sold it at a loss.
She also said she had confronted the oil industry in her state. "Whatever they're running now, it is not the state of Alaska," she said.
