Amid the biting economic crisis, the White House contenders are adopting different styles: Republican John McCain is on the attack against his rival, while Democrat Barack Obama has urged calm.
"Now is the time to come together with the determination that we can steer ourselves out of this crisis and restore confidence in the American economy," Obama told an Ohio rally Friday.
He was speaking as global markets continued their freefall, after Wall Street opened Friday with sharp losses before limping upwards, only to plunge again on comments from US President George W. Bush.
"Now is not the time for fear or panic, now is the time for resolve, for leadership," Obama had urged thousands of people Thursday at the start of a two-day bus tour through the critical midwestern swing state of Ohio.
On Friday he lambasted McCain for spreading a politics of "fear or panic."
"It's easy to rile up a crowd by stoking anger and division," Obama said. "But that is not what we need now in the United States, the times are too serious."
The tone of the Republican campaign has deteriorated since Republican vice presidential pick Sarah Palin on Saturday accused Obama of "palling around with terrorists."
She was referring to 1960s radical William Ayers, a co-founder of the Weather Underground, a faction that carried out bomb attacks in the United States.
The McCain campaign Friday unveiled its hardest hitting ad yet against Ayers, a member of the Weather Underground Group, whom Obama met in his formative years in Chicago politics.
"When convenient, he worked with terrorist Bill Ayers," the ad script said. "When discovered, he lied. Obama. Blind ambition. Bad judgment."
In another ad released Thursday, the Republican campaign bluntly said Obama was "too risky for America."
The Democratic nominee, 47, has repeatedly said he is not close to Ayers, although in the past they did serve on the same charitable foundation.
But McCain, 72, and Palin, 44, have accused Obama of lying, insisting he should come clean on his past associations.
Obama has said he can put up with four more weeks of character attacks ahead of the November 4 elections, but says McCain would represent four more years of Bush policies in the White House.
Washington Post editorialist E.J. Dionne said today's race had echoes of the the 1932 presidential campaign, when the country was suffering under the weight of the Great Depression.
Then Republican White House hopeful Herbert Hoover sought to defeat his Democratic rival Franklin D. Roosevelt by playing on the fears of a desperate nation.
Roosevelt adopted a more optimistic line, and won the elections. And in his somber, first inaugural address in January 1933, in which he blamed banks and financial institutions for the crisis, he warned "the only thing we have to fear is fear itself."
Dionne wrote: "It's too early to predict that the 2008 campaign will turn out like the one in 1932.
"But history suggests that in American elections, the candidate who underestimates his opponent often loses, and hope almost always beats fear."
The Republican campaign was Friday awaiting the release of a report into abuse of power allegations against Palin.
The inquiry has been probing allegations that Palin abused her office as Alaska governor by sacking a public safety commissioner, Walt Monegan, for his failure to dismiss a state trooper who was her former brother-in-law.
Members of Alaska's Legislative Council were to begin a closed-doors meeting in Anchorage at 9:00 am (1700 GMT) and would then vote on whether to make the 263-page report public, possibly later Friday, officials told AFP.
Meanwhile, Obama's campaign confirmed it was buying up half-hour chunks of prime-time television time on top US networks for a pre-election broadcast in the final week of the White House race.
A campaign aide said that the campaign had secured time on NBC and would also look to buying a slot on Fox. The Hollywood Reporter said the campaign had bought a half hour of airtime on CBS on October 29 at 8:00 pm.
