LANCASTER, Ohio -- At his field office in this small town outside Columbus, Steve Davis, the local county Republican chairman, has seen the polls showing Sen. John McCain trailing Democratic rival Sen. Barack Obama. But he takes comfort in other numbers: 6,100 McCain-for-president yard signs distributed in Fairfield County this year versus 2,500 Bush signs in 2004.

Outside Cincinnati, some 100 miles to the southeast, Lori Viars is feeling good, too. This anti-abortion activist has put pro-McCain fliers on windshields in church parking lots, spent hours making phone calls and participated in "prayer conference calls," where people can dial in and pray together for a Republican win.

Both Ms. Viars and Mr. Davis live in Republican counties just outside major Ohio cities, the exurbs where Sen. McCain must run up the score if he hopes to win the state on Tuesday. It was here that President George W. Bush pulled out a narrow victory in 2004, drawing thousands more voters to the polls than outside experts thought possible, and ultimately clinching the race.

One key to Mr. Bush's re-election was the Republican party's nationwide get-out-the vote effort in the final 72 hours before election day. Operatives and activists built on months of phone calls and door knocks to turn out an unprecedented number of supporters from the conservative base.

Heading into the crucial final weekend, Republicans say their operation is even stronger and running ahead of where they were four years ago at this time. They say their targeting is more efficient, their workers more experienced and their technology better. The McCain campaign, using an operation funded by the Republican National Committee, has already made 19.6 million phone calls this year nationwide. That's more than 2004, says Mike DuHaime, Sen. McCain's political director. And 2004, he says, "was the gold standard for turnout."

Officials expect to make more than 15 million contacts, including phone calls and door knocks, just in these final days.

But Republicans also have a lot more ground to make up than they did four years ago. Back then, most polls showed Mr. Bush tied or with a narrow lead against his Democratic opponent Sen. John Kerry. In contrast, Sen. McCain has trailed Sen. Obama in every major national poll since mid-September. Polls show Sen. Obama with leads in enough battleground states to be able to secure an electoral-vote victory. He also has a stronger ground operation than Sen. Kerry had. In recent days, traders on Intrade, the political futures market, have given Sen. Obama a more than 80% chance of winning.

McCain aides say a victory Tuesday is still possible. Some national polls have shown a tightening of the race, with Sen. Obama's lead down to as little as three percentage points. Bill McInturf, Sen. McCain's chief pollster, argued this week that Sen. McCain is closing the gap in battleground states, gaining among non-college-educated men, rural voters, abortion opponents who vote on that issue, and Democrats who do not strongly identify with the party.

Mr. McInturf also says the campaign is seeing improvement with what he calls "Wal-Mart women," women without a college degree in households earning under $60,000. McCain aides say that his new focus on taxes, an argument centered on "Joe the Plumber" and his fears of rising taxes under Sen. Obama, is finally resonating.

And while analysts predicting an Obama victory point to signs of a record turnout among African-Americans and young people, two groups that overwhelmingly favor the Democrat, Mr. McInturf says there could also be a record turnout among working-class whites. He says that group may be more receptive to Sen. McCain's message.