LAS VEGAS --The TV ads thrum back-to-back, hour after hour: Republican Sen. Dean Heller wants taxpayers to subsidize oil companies. Democratic Rep. Shelley Berkley is flipping foreclosed homes for profit. He wants to ship jobs overseas and strip health coverage from the elderly; she used her position in Congress to enrich her husband.
Nevada voters are enduring a numbing, on-air spectacle in the closing days of the state's toss-up Senate race - there are even ads telling voters to ignore the ads. But the TV screen is only one window on the critical battleground - the outcome is likely to hinge on a furious push by President Barack Obama and Mitt Romney to turn out voters in the politically divided state.
The stakes extend beyond Nevada to the broader battle for control of the Senate. If Obama wins reelection, Republicans must gain four seats to take the majority, or three if Romney prevails. And presidential coattails could make a difference.
With Democrats encouraged by a 90,000-voter edge statewide, "the higher the voter turnout, I think the better for President Obama and the better for me," says Berkley, who's lagged behind the president in most polling.
Statewide contests are rarely giveaways in Nevada, the nation's gambling mecca where years of growth and a fast-growing Hispanic population helped transform a former Republican fortress into one of the nation's most politically competitive states.
Election Day predictions are especially shaky this year, given Nevada's signature independent streak, a history of ticket-splitting and anger over the state's blistered economy - Nevada's jobless rate, now 11.8 percent.
"We've always viewed ourselves as the underdog in this race," says Heller campaign chief Mac Abrams.
Berkley and Heller have been in Congress for years, but they've each struggled to become known in areas outside their home turf. And it's not clear which way newly registered voters who might know little, if anything, about them, will turn.
The candidates offer voters a choice as stark as the presidential race.
Heller, 52, is a buttoned-down Mormon who was in his third term in the House representing a conservative, mostly rural district in Northern Nevada before being appointed to the Senate after John Ensign exited amid a sex scandal. Berkley, 61, a lawyer, is a buoyant conversationalist who retains traces of a New York accent, hinting where she spent her early years. The seven-term congresswoman lives in Las Vegas, making the race as battle between sometimes contentious regions, as well as political parties.
They've squabbled over immigration, congressional budgets, Medicare and how to help Main Street. She backed an overhaul of Wall Street oversight after the 2008 financial crisis, he opposed it. Heller rejected an increase in the minimum wage in 2007, she supported it. Berkley supports, and Heller opposes, the so-called Dream Act, which would allow young people brought to the U.S. without authorization to avoid deportation if they graduate high school or join the military.
Ryan Moore, 30, a casino valet, said he liked Romney but pulled the lever for Berkley and Obama at an early voting site because he believes the president's health care overhaul needs time to work.
Heller says the law will raise taxes and kill jobs, while Berkley backed it.
"It's a broken health care system right now," says Moore, a registered independent who was once stranded without coverage after being cut loose from a previous job. As far as whether the president's plan will work, "all you have right now is speculation."
To mobilize voters, Democrats are benefiting from a finely tuned political machine honed by Senate Majority Leader Harry Reid, D-Nev., who's been working overtime to get Berkley in the Senate. It's no coincidence she's using the same pollster, mail and online consultants who helped steer Reid to victory in a tough race in 2010. Meanwhile, Romney's campaign has invested heavily in building a rival operation to stand in for a state GOP long fractured by infighting.
No one is predicting a repeat performance for Obama, who captured Nevada with a commanding 12-point margin over John McCain in 2008. He could give Berkley a potentially decisive boost if he's able to score a significant win, particularly in areas outside Las Vegas where she's not well known.
Early voting that started Oct. 20 showed Democrats opening up a lead in overall numbers, but voters in both parties were casting ballots in numbers greater than in 2008.
"Over the last six or eight years, Democrats have built an incredibly strong organization," conceded Republican consultant Ryan Erwin, who is advising the Romney campaign in Nevada. "We are not as good as they are yet, but we've come a long, long way."
With control of the Senate in play, super PACs, unions and other outside groups have flooded the state with more than $20 million in spending on the race so far, outpacing the $17 million raised by the candidates' campaigns. It's a remarkable spending spree in a state with 1.2 million voters.
If Berkley's fate could rise or fall with Obama, a Heller victory could turn on his popularity outside Democratic-thick Clark County, as well as his appeal among fickle independents who comprise roughly 17 percent of the electorate.
While Berkley has lagged Obama in some polling, Heller has hovered just above Romney, including with Hispanics.
There is frequent ticket-splitting in the state. In 2010 Reid was re-elected in the same year Nevadans picked Gov. Brian Sandoval, a Republican, and Heller carried swing-voting Washoe County in 2008, the same year Obama buried McCain.
Heller declined an interview request through a spokeswoman, but campaign manager Abrams predicted a Romney surge. He argued that Heller could still emerge on top even if Obama wins the state..
"We might be slightly undermanned from what the Reid machine has, but we are working three or four times harder," Abrams said.